Soil mercury levels in the area surrounding the Cerro Prieto geothermal complex, MEXICO.

Even though geothermal energy is a renewable energy source that is seen as cost-effective and environmentally friendly, emissions from geothermal plants can impact air, soil, and water in the vicinity of geothermal power plants. The Cerro Prieto geothermal complex is located 30 km southeast of the city of Mexicali in the Mexican state of Baja California. Its installed electricity generation capacity is 720 MW, being the largest geothermal complex in Mexico. The objective of this study was to evaluate whether the emissions generated by the geothermal complex have increased the soil mercury concentration in the surrounding areas. Fifty-four surface soil samples were collected from the perimeter up to an approximate distance of 7660 m from the complex. Additionally, four soil depth profiles were performed in the vicinity of the complex. Mercury concentration in 69 % of the samples was higher than the mercury concentration found at the baseline sites. The mercury concentration ranged from 0.01 to 0.26 mg/kg. Our results show that the activities of the geothermal complex have led to an accumulation of mercury in the soil of the surrounding area. More studies are needed to determine the risk to human health and the ecosystems in the study area.

gamma-Amino-beta-hydroxybutyric acid as add-on therapy in adult patients with severe focal epilepsy.

Total seizure frequency was evaluated among adult patients with severe partial epilepsy refractory to medical treatment. Clinical status was assessed before, and after a synthetic analog of gamma-amino-beta-hydroxybutyric acid (GABOB) was used as add-on therapy. Twenty-five patients with temporal and frontal lobe epilepsy were included in the trial. They received GABOB 250 mg twice daily during a 26-week period. Concentrations of concomitant antiepileptic medication were not modified. Twenty-five percent of the patients showed a 50% reduction of the total seizure frequency. There were no serious adverse effects related to medication.

Surgical treatment of complex partial seizures: 20 years' experience.

From 1972 to 1992 inclusive, the author performed 263 surgical procedures for the relief of intractable epilepsy. The purpose of this report is to review 112 temporal lobectomies for the treatment of drug-resistant complex partial seizures. There were 90 adults and 22 children, in whom there were 61 left-sided procedures and 51 right-sided ones. All these cases represent 10% of 2,676 epileptics seen at the Osler Clinic during the last 20 years. The results were evaluated in four groups: 60 patients belonging to group A were seizure-free, group B comprised 24 patients with a reduction in seizures of 75%, group C which included 17 cases had minimal improvement, and finally group D with 11 patients showed no improvement at all. The factors of good surgical outcome were analyzed in 60 patients. The total number of patients that substantially improved after surgery represented 74.5% of the whole series with no mortality and a morbidity of 1.8%.

Corpus callosum section for patients with intractable epilepsy.

Microsurgical techniques of callosotomy were effective in relieving medically intractable epilepsy in 14 of 16 patients. Intra-arterial digital angiography has been used preoperatively to assess drainage of the veins of the frontal lobe. MRI is useful in verifying the postoperative extent of corpus callosum section. Patients with bilateral frontal lesions and unilateral destructive lesions responded to callosotomy. None of the patients had an increase in seizures after the procedure.