ABSTRACT
In the present study patients with previously diagnosed MRI-negative temporal lobe epilepsy (TLE) on long-term video electroencephalography (VEEG) monitoring were re-evaluated with high resolution 3T MRI brain to look out for a skull base temporal lobe encephalocoele (TE). A total of 234 VEEGs were analyzed. TLE had been diagnosed in 104 patients based on semiology, ictal, interictal EEG data, and brain positron emission tomography (PET) studies. Of these, 99 patients had temporal lobe abnormality (78 had mesial temporal sclerosis, 8 had tumor, 3 had focal cortical dysplasia, and 10 had mixed pathology). Out of the five 1.5T MRI-negative TLE patients, two patients were diagnosed with TE on subsequent 3T MRI brain scans and one patient underwent electrocorticography-guided tailored resection for complete removal of epileptogenic tissue; with Engels class I seizure freedom at one year follow-up. We propose that TE should be carefully searched for, as a cause of refractory TLE, using high-resolution MRI sequences.
ABSTRACT
This paper describes a reductive amination crosslinking protocol that facilitates identification and characterization of a class of DNA repair enzymes, DNA glycosylase/AP lyases, which are involved in base excision repair. This crosslinking technique has been used to identify enzymes in crude extracts and in partially purified enzyme preparations, to isolate proteins for sequencing, and to confirm the reaction mechanism of members of this enzyme family. Chemical reduction of the Schiff's base enzyme-substrate intermediate to a stable amine results in the formation of an irreversible covalent bond between the substrate lesion situated within a 2'-deoxyoligonucleotide and the repair enzyme. This complex can be detected by gel electrophoresis and can also be isolated and analyzed by amino acid sequencing.
