Effect of acrylamide on neurological recovery following spinal cord injury in rats

Acrylamide (ACR) is a cumulative neurotoxin which causes axonal degeneration in animals and man. Industrial workers exposed to ACR have been reported to suffer from a variety of central and peripheral neuropathological symptoms including numbness of hands and feet, skin peeling and muscular weakness of legs. These reports suggest that the body burden of ACR may be a risk factor in recovery patterns following neurotrauma. The present study was designed to assess the effect of ACR on neurological recovery following spinal cord injury (SCI) in rats. Male Sprague-Dawley rats weighing 200-230 g were anaesthetised with chloral hydrate and laminectomy was performed at T 7-8 level leaving the dura intact. A compression plate (2.2 x 5.0 mm) loaded with a weight of 35 g was placed on the exposed cord for 5 minutes. Animals were divided into seven groups of eight rats each. The animals in Group 1 served as control whereas rats in Group 2 underwent laminectomy alone (sham). The rats in Group 3 to 6 were subjected to SCI as mentioned above. Animals in Groups 4, 5 and 6 also received ACR in the doses of 10 mg/kg, 20 mg/kg and 40 mg/kg, i.p., respectively in addition to SCI, whereas the rats in Group 7 received ACR alone at a dose of 40 mg/kg body weight. The first dose of ACR was given 30 minutes before SCI, followed by daily administration of drug for 7 days. Post traumatic neurological recovery was recorded daily for 10 days using a modified Tarlov score, inclined plane test and sensory and vocal score. Electrophysiological changes were assessed using somatosensory and corticomotor evoked potentials. The animals were sacrificed at different time intervals and the injured site of the spinal cord was analysed for lipid hydroperoxides (LPH), conjugated dienes (CD) and glutathione (GSH). Neuropathological changes in the spinal cord were assessed using light microscopy. The rats exposed to compression injury alone showed a maximum neurological deficit at 24 hr and then a gradual recovery was observed over a period of 10 days. The rats treated with ACR along with SCI showed poor or no recovery over a period of 10 days. Our electrophysiological and histopathological studies also confirmed that concomitant exposure to ACR produces a significant deleterious effect on the recovery from SCI. SCI induced increase in oxidative stress (increase in LPH and CD and decrease in GSH) is also exacerbated by ACR suggesting a role of free radicals. The results of this study suggest that increased body burden of ACR may retard the recovery from neurotrauma or even lead to permanent disability

Effect of aluminum on neurological recovery in rats following spinal cord injury

Object. This investigation was undertaken to study the effect of aluminum on neurobehavioral, electrophysiological, structural, and biochemical changes in rats following spinal cord injury (SCI)

Small molecules that reactivate p53 in renal cell carcinoma reveal a NF-κB-dependent mechanism of p53 suppression in tumors

Renal cell carcinomas (RCC) commonly retain wild-type but functionally inactive p53, which is repressed by an unknown dominant mechanism. To help reveal this mechanism, we screened a diverse chemical library for small molecules capable of restoring p53-dependent transactivation in RCC cells carrying a p53-responsive reporter. Among the compounds isolated were derivatives of 9-aminoacridine (9AA), including the antimalaria drug quinacrine, which strongly induced p53 function in RCC and other types of cancer cells. Induction of p53 by these compounds does not involve genotoxic stress and is mediated by suppression of NF-κB activity. In contrast to agents that target IκB kinase 2, 9AA and quinacrine can effectively suppress both basal and inducible activities of NF-κB, representing inhibitors of a previously undescribed type that convert NF-κB from a transactivator into a transrepressor, leading to accumulation of inactive nuclear complexes with unphosphorylated Ser-536 in the p65/RelA subunit. p53 function in RCC can be restored by ectopic expression of a superrepressor of IκB as effectively as by 9AA-derived compounds. These findings suggest that the complete or partial repression of p53 observed in many tumors can be the result of constitutive activation of NF-κB. The results demonstrate, in principle, the possibility to kill cancer cells selectively through simultaneous inhibition of NF-κB and activation of p53 by a single small molecule and suggest anticancer applications for the well known antimalaria drug quinacrine