Quantitative Analysis of Remineralization of Artificial Carious Lesions with Commercially Available Newer Remineralizing Agents Using SEM-EDX- In Vitro Study".

INTRODUCTION: The basic principle of remineralization is by advocating a biological or non-invasive approach rather than the surgical approach for early enamel lesions. There are relatively newer products available for remineralization, latest being the resin-infiltration technique, commercially available as Icon. AIM: The aim of the study was to evaluate the remineralizing potential of Casein Phosphopeptide-Amorphous Calcium Phosphate (CPP-ACP), Vantej and Icon by the quantitative evaluation of mineral gain. MATERIALS AND METHODS: Seventy eight maxillary premolars were decoronated at Cemento-Enamel Junction (CEJ) and then sectioned mesio-distally using diamond disc into two halves. Mineral content of the sound specimens were recorded using Energy Dispersive X-ray (EDAX) micro-analyser. The samples were then subjected to demineralization by using demineralizing solution. The samples were grouped (n=26) based on the remineralizing agent used, Group 1: Vantej, Group 2: CPP-ACP, Group 3: Icon. After the application of remineralizing agent, the mineral content was measured using EDAX. RESULTS: After remineralization, there was a significant difference between the groups when calcium and phosphorous ratios (Ca:P) were compared, showing greater potential of remineralization for CPP-ACP followed by Vantej and Icon group. CONCLUSION: CPP-ACP performed better than Vantej and Icon in remineralizing the demineralized enamel.

Neuroprotective effects of erythropoietin on acute metabolic and pathological changes in experimentally induced neurotrauma.

OBJECT: Head trauma is a dynamic process characterized by a cascade of metabolic and molecular events. Erythropoietin (EPO) has been shown to have neuroprotective effects in animal models of traumatic brain injury (TBI). Acute in vivo mechanisms and pathological changes associated with EPO following TBI are unknown. In this study the authors compare acute metabolic and pathological changes following TBI with and without systemically administered EPO. METHODS: Right frontal lobe microdialysis cannulae and right parietal lobe percussion hubs were inserted into 16 Sprague-Dawley rats. After a 4- to 5-day recovery, TBI was induced via a DragonFly fluid-percussion device at 2.5-2.8 atm. Rats were randomized into 2 groups, which received 5000 U/kg EPO or normal saline intraperitoneally 30 minutes after TBI. Microdialysis samples for glucose, lactate, pyruvate, and glutamate were obtained every 25 minutes for 10 hours. Rats were killed, their brains processed for light microscopy, and sections stained with H & E. RESULTS: Erythropoietin administered 30 minutes after TBI directly affects acute brain metabolism. Brains treated with EPO maintain higher levels of glucose 4-10 hours after TBI (p<0.01), lower levels of lactate 6-10 hours after TBI (p<0.01), and lower levels of pyruvate 7.5-10 hours after TBI (p<0.01) compared with saline-treated controls. Erythropoietin maintains aerobic metabolism after TBI. Systemic EPO administration reduces acute TBI-induced lesion volume (p<0.05). CONCLUSIONS: Following TBI, neuron use initially increases, with subsequent depletion of extracellular glucose, resulting in increased levels of extracellular lactate and pyruvate. This energy requirement can result in cell death due to increased metabolic demands. These data suggest that the neuroprotective effect of EPO may be partially due to improved energy metabolism in the acute phase in this rat model of TBI.

Tumor anorexia: effects on neuropeptide Y and monoamines in paraventricular nucleus.

Paraventricular (PVN) concentrations of neuropeptide Y (NPY), serotonin (5-HT) and dopamine (DA) in anorectic tumor-bearing (TB) rats were measured before and after tumor resection. At onset of anorexia in TB versus non-tumor bearing (NTB) Controls 5-HT increased from 12.19+/-0.49 pg/microg to 14.89+/-0.81 pg/microg ( P<0.05 ) while DA and NPY decreased from 7.34+/-0.42 pg/microg to 4.97+/-0.56 pg/microg and 23.47+/-4.27 pg/microg to 13.64+/-1.44 pg/microg, respectively ( P<0.05 ). After tumor resection, these neuromediators normalized when compared to sham-operated NTB rats. NTB pair-fed Controls were also studied. We conclude that the increased 5-HT and the decreased DA and NPY concentrations in PVN are associated with cancer anorexia and that the NPY food stimulatory effect is linked to serotoninergic and dopaminergic systems in hypothalamus.