Selected Molecular Targets for Antiepileptogenesis.

The term epileptogenesis defines the usually durable process of converting normal brain into an epileptic one. The resistance of a significant proportion of patients with epilepsy to the available pharmacotherapy prompted the concept of a causative treatment option consisting in stopping or modifying the progress of epileptogenesis. Most antiepileptic drugs possess only a weak or no antiepileptogenic potential at all, but a few of them appear promising in this regard; these include, for example, eslicarbazepine (a sodium and T-type channel blocker), lamotrigine (a sodium channel blocker and glutamate antagonist) or levetiracetam (a ligand of synaptic vehicle protein SV2A). Among the approved non-antiepileptic drugs, antiepileptogenic potential seems to reside in losartan (a blocker of angiotensin II type 1 receptors), biperiden (an antiparkinsonian drug), nonsteroidal anti-inflammatory drugs, antioxidative drugs and minocycline (a second-generation tetracycline with anti-inflammatory and antioxidant properties). Among other possible antiepileptogenic compounds, antisense nucleotides have been considered, among these an antagomir targeting microRNA-134. The drugs and agents mentioned above have been evaluated in post-status epilepticus models of epileptogenesis, so their preventive efficacy must be verified. Limited clinical data indicate that biperiden in patients with brain injuries is well-tolerated and seems to reduce the incidence of post-traumatic epilepsy. Exceptionally, in this regard, our own original data presented here point to c-Fos as an early seizure duration, but not seizure intensity-related, marker of early epileptogenesis. Further research of reliable markers of early epileptogenesis is definitely needed to improve the process of designing adequate antiepileptogenic therapies.

Anti-Epileptogenic Effects of Antiepileptic Drugs.

Generally, the prevalence of epilepsy does not exceed 0.9% of the population and approximately 70% of epilepsy patients may be adequately controlled with antiepileptic drugs (AEDs). Moreover, status epilepticus (SE) or even a single seizure may produce neurodegeneration within the brain and SE has been recognized as one of acute brain insults leading to acquired epilepsy via the process of epileptogenesis. Two questions thus arise: (1) Are AEDs able to inhibit SE-induced neurodegeneration? and (2) if so, can a probable neuroprotective potential of particular AEDs stop epileptogenesis? An affirmative answer to the second question would practically point to the preventive potential of a given neuroprotective AED following acute brain insults. The available experimental data indicate that diazepam (at low and high doses), gabapentin, pregabalin, topiramate and valproate exhibited potent or moderate neuroprotective effects in diverse models of SE in rats. However, only diazepam (at high doses), gabapentin and pregabalin exerted some protective activity against acquired epilepsy (spontaneous seizures). As regards valproate, its effects on spontaneous seizures were equivocal. With isobolography, some supra-additive combinations of AEDs have been delineated against experimental seizures. One of such combinations, levetiracetam + topiramate proved highly synergistic in two models of seizures and this particular combination significantly inhibited epileptogenesis in rats following status SE. Importantly, no neuroprotection was evident. It may be strikingly concluded that there is no correlation between neuroprotection and antiepileptogenesis. Probably, preclinically verified combinations of AEDs may be considered for an anti-epileptogenic therapy.

Bioleaching of metals from printed circuit boards supported with surfactant-producing bacteria.

This study has evaluated the possibility of bioleaching zinc, copper, lead, nickel, cadmium and chromium from printed circuit boards by applying a culture of sulphur-oxidising bacteria and a mixed culture of biosurfactant-producing bacteria and sulphur-oxidising bacteria. It was revealed that zinc was removed effectively both in a traditional solution acidified by a way of microbial oxidation of sulphur and when using a microbial culture containing sulphur-oxidising and biosurfactant-producing bacteria. The average process efficiency was 48% for Zn dissolution. Cadmium removal was similar in both media, with a highest metal release of 93%. For nickel and copper, a better effect was obtained in the acidic medium, with a process effectiveness of 48.5% and 53%, respectively. Chromium was the only metal that was removed more effectively in the bioleaching medium containing both sulphur-oxidising and biosurfactant-producing bacteria. Lead was removed from the printed circuit boards with very low effectiveness (below 0.5%). Aerating the culture medium with compressed air increased the release of all metals in the medium with sulphur and biosurfactant, and of Ni, Cu, Zn and Cr in the acidic medium. Increasing the temperature of the medium (to 37°C) had a more significant impact in the acidic environment than in the neutral environment.

Hemithorax irradiation for Ewing tumors of the chest wall.

PURPOSE: In the Cooperative Ewing's Sarcoma Study 86 and the European Intergroup Cooperative Ewing's Sarcoma Study 92, hemithorax irradiation (RT) was performed in patients with Ewing tumors of the chest wall involving the pleura or contaminating the pleural cavity. In a retrospective analysis, the outcomes of these patients were evaluated and compared with those of patients with chest wall tumors who did not receive hemithorax RT. METHODS AND MATERIALS: Between 1985 and 1996, 138 patients presented with nonmetastatic Ewing tumors of the chest wall. They were treated in a multimodal treatment regimen that included polychemotherapy and local therapy depending on the tumor characteristics. Hemithorax RT was performed at a dose of 15 Gy for patients <14 years old and 20 Gy for patients >or=14 years old. Forty-two patients received hemithorax RT (Group 1) and 86 patients did not (Group 2). The data were insufficient for the other 10 patients. RESULTS: Comparing both groups, the initial pleural effusion, pleural infiltration, and intraoperative contamination of the pleural space were significantly more frequent in Group 1. The event-free survival rate after 7 years was 63% for patients in Group 1 and 46% for patients in Group 2 (not statistically significant). The 7-year local relapse rate (including combined local-systemic relapses) was 12% in Group 1 and 10% in Group 2; the corresponding systemic relapse rates were 22% and 39%. CONCLUSION: Patients with chest wall tumors who received hemithorax RT were negatively selected; yet the rate of event-free survival was better for patients who received hemithorax RT than for those who did not (although the difference was not statistically significant). This result was due to a reduction of metastases, mainly lung metastases. Local control was equivalent between the two groups. These favorable results have caused us to continue using hemithorax RT to treat high-risk patients with Ewing tumors of the chest wall.