Calbindin overexpression buffers hippocampal cultures from the energetic impairments caused by glutamate.

A dramatic rise in free cytosolic calcium concentration is thought to be a central event in the pathogenesis of glutamate excitotoxicity in neurons. We have previously demonstrated that gene transfer of the calcium-binding protein calbindin D28k via a Herpes simplex amplicon vector decreases the rise in intracellular calcium and promotes cell survival following glutamatergic challenge. This study explores the effect of calbindin transgene expression on cellular metabolism following glutamate excitotoxicity. Because excitotoxic insults are often energetic in nature, and because calcium sequestering and extrusion place heavy energy demands on a cell, we hypothesized that calbindin overexpression may help preserve cellular energy levels during an insult. We overexpressed calbindin in primary hippocampal cultures, using a Herpes simplex amplicon vector system. We found that calbindin overexpression protected neurons from the decline in ATP levels, mitochondrial potential and metabolic rate following a glutamatergic insult. These results indicate that calbindin expression helps preserve cellular energy state following glutamate excitotoxicity. This illustrates the energetic load placed on neurons by increased free cytosolic calcium and may help explain the neuroprotective effects of calbindin.

Gene therapy effectiveness differs for neuronal survival and behavioral performance.

If neuronal gene therapy is to be clinically useful, it is necessary to demonstrate neuroprotection when the gene is introduced after insult. We now report equivalent neuronal protection if calbindin D(28K) gene transfer via herpes simplex virus amplicon vector occurs immediately, 30 min, or 1 h after an excitotoxic insult, but not after a 4 h delay. Behavioral performance was evaluated for immediate and 1 h delay groups using a hippocampal-dependent task. Despite equivalent magnitude and pattern of sparing of neurons with the immediate and 1 h delay approaches, the delay animals took a significantly longer time after insult to return to normal performance.

Free radicals are involved in the damage to protein synthesis after anoxia/aglycemia and NMDA exposure.

Neuronal protein synthesis is inhibited in CA1 pyramidal neurons for many hours after ischemia, hypoxia or hypoglycemia. This inhibition precedes cell death, is a hallmark characteristic of necrotic damage and may play a key role in the death of vulnerable neurons after these insults. The sequence of events leading to this inhibition remains to be fully elucidated. The protein synthesis failure after 7.5 min anoxia/aglycemia in the rat hippocampal slice can be prevented by blocking N-methyl-D-aspartate receptors in a reduced calcium environment during the insult. In this study, we demonstrate that N-methyl-D-aspartate exposure directly causes a dose-dependent, receptor-mediated and prolonged protein synthesis inhibition in CA1 pyramidal neurons. The free radical scavenger Vitamin E significantly attenuates this damage due to low concentrations of N-methyl-D-aspartate (10 microM). Free radical generation by xanthine/xanthine oxidase (XOD) can directly damage protein synthesis in neurons of the slice. Vitamin E, ascorbic acid and N-acetylcysteine can each prevent the damage due to anoxia/aglycemia and to higher concentrations of N-methyl-D-aspartate (50 microM), provided calcium levels are reduced concomitantly. These findings indicate that both free radicals and calcium play a role in the sequence of events leading to protein synthesis failure after energetic stress like anoxia/aglycemia. They further suggest that the mechanism by which N-methyl-D-aspartate receptor activation damages protein synthesis involves free radical generation.

[Effectiveness of dermatologic minor surgery in the office of the family physician and patient satisfaction in relation with ambulatory surgery]. / Efectividad de la cirugía menor dermatológica en la consulta del médico de familia y satisfacción del paciente en relación con la cirugía ambulatoria.

BACKGROUND: The minor surgery by family physicians increase the primary care competences. The purpose of this work is to prove patients' satisfaction and minor surgery effectiveness practiced by family physicians in health centers with respect to ambulatory's general surgeon. MATERIAL AND METHODS: Case-control retrospective study, comparing dermatological surgical procedures performed by 4 family physicians and 8 3rd-year Family Physician residents with surgical procedures wade made by a surgeon over one a year period. Variables analysed include: descriptive samples homogeneity, surgery effectiveness (waiting time, esthetic results, healing time and number of visits, and histopathologic correlation) and patients' satisfaction (with the waiting time, with the results of surgery and with the physician). RESULTS: Minor surgical procedures carried out by 146 family physicians and 61 general surgeons were compared, in congruence with the analyzed descriptive homogeneity's parameters. Family physicians average waiting time was the lower, with a mean of 45 days less than the surgeon. Patient's satisfaction with the physician was higher when family physician were involved (p < 0.001); the same could be applied for the waiting time (p < 0.001). There were no significant differences over the effectiveness and patients' satisfaction. CONCLUSION: The dermatologic minor surgery by family physician is effective, satisfactory for patients, and has less waiting time. This results justify the introduction of minor surgery in the family physicians office.