Periodic lateralized epileptiform discharges: etiology, clinical aspects, seizures, and evolution in 130 patients.

The purpose of this study was to analyze the clinical aspects in 130 patients presenting periodic lateralized epileptiform discharges (PLEDs) in their EEG and to compare these results with those found in the literature. Etiology, neurologic deficit, seizure occurrence, and evolution were studied in each patient by historical review. The recordings were obtained on 8- or 16-channel EEGs with electrode placement according to the International 10-20 System. Recordings containing PLEDs were selected. PLEDs were defined as repetitive periodic, focal, or hemispheric epileptiform discharges (spikes, spike and waves, polyspikes, sharp waves) usually recurring every 1 to 2 seconds. The statistical study was carried out via the chi(2) test using the computer program SPSS. The main etiology found in this group of patients was stroke (61 of 130 patients). Other processes found were brain infections, tumors, hematomas, and several other entities grouped together as miscellaneous (anoxic encephalopathy, subarachnoid hemorrhage, craniocerebral trauma, Creutzfeldt-Jacob disease, migraine, multiple sclerosis, and aminophylline intoxication). Half of these patients (65 of 130) developed seizures, mostly partial motor seizures. No significant relation between etiology and seizures was found (chi(2) = 2.81, P = 0.4222). Seizures recurred in 14 of 130 patients during a follow-up of 14.5 months. PLEDs were not recorded in any EEG at the time of seizure recurrence. PLEDs constitute a distinctive but uncommon EEG phenomenon of repetitive, periodic, and stereotyped lateralized complexes. In agreement with the literature, PLEDs were associated with an acute process and occurred early during the course of the illness in all patients studied and were usually associated with structural lesions, with stroke being the main etiology. Traditionally, seizures occur with PLEDs but it is also accepted that they can exist in patients who never develop epileptic activity, either clinically or electrically, as demonstrated in 50% of the patients studied. No significant association between seizures and any etiology could be found. It was not demonstrated that the occurrence of seizures may influence the outcome in any way.     

Immunocytometric characteristics of a monoclonal antibody (Bra55) recognizing the leukocyte common antigen (LCA)

The immunofluorescence cytofluorometric reactivity pattern of monoclonal antibody Bra55 (IgG1) elicited with a non-T, non-B ALL cell line (REH), with a panel of human neoplastic hemopoietic cell lines (including non-T, non-B, T and myeloid leukemia cell lines) and with isolated peripheral blood lymphocytes, monocytes and granulocytes from healthy donors corresponded to the previously described microscopic immunofluorescence, ELISA, immunoprecipitation and immunocytochemic data indicating that this monoclonal antibody recognizes a 170-220 kDa cell surface glycoprotein (leukocyte common antigen) expressed selectively on hemopoietic cells. The purified, FITC-conjugated Bra55 monoclonal antibody was effectively inhibited in its binding to the surface of LCA-positive cells by reference anti-LCA monoclonal antibodies; no inhibition of this activity by LCA-unrelated monoclonal antibodies (such as anti-MHC class I and class II antibodies) was observed. These data confirm the previously reported hemopoietic cell specificity (anti-LCA, CD45) of the Bra55 monoclonal antibody.     

Temporal sequence of gene expression leading caudal prosencephalon to develop a midbrain/hindbrain phenotype.

Transplantation of prosomeres 1-2 into the cerebellar plate were used, by using chick/quail chimeras, to analyse the temporal sequence of the genetic cascade leading the graft to develop a midbrain/hindbrain phenotype. Our results show that (1) at Hamburger and Hamilton (HH) stage 13, Pax2 and En2 are already induced within the graft, before all other genes of the cascade, whereas misexpression of Fgf8 is also observed within the contiguous host cerebellar plate; (2) within the graft, Otx2 repression and Gbx2 induction (see Hidalgo-Sánchez et al. [1999] Development 126:3191-3203) are secondary events that affect, from stages HH14-15, the areas in contact with the host Gbx2/Fgf8-expressing cerebellar plate; (3) at these stages, the repressed Otx2 territory extends beyond the areas induced to express Gbx2, with the two territories not abutting before HH17-18; (4) Fgf8 expression becomes progressively induced within the Otx2-repressed/Gbx2-induced territory, starting at HH15-16. Our results support the hypothesis that the host-Gbx2/graft-Otx2 interface could trigger the genetic cascade induced within the graft and that the Gbx2-induced domain could play a key role during the establishment of the induced intragraft midbrain/hindbrain boundary.     

Genetic ablation of the t-SNARE SNAP-25 distinguishes mechanisms of neuroexocytosis.

Axon outgrowth during development and neurotransmitter release depends on exocytotic mechanisms, although what protein machinery is common to or differentiates these processes remains unclear. Here we show that the neural t-SNARE (target-membrane-associated-soluble N-ethylmaleimide fusion protein attachment protein (SNAP) receptor) SNAP-25 is not required for nerve growth or stimulus-independent neurotransmitter release, but is essential for evoked synaptic transmission at neuromuscular junctions and central synapses. These results demonstrate that the development of neurotransmission requires the recruitment of a specialized SNARE core complex to meet the demands of regulated exocytosis.     

Antiepileptic drugs in schizophrenia: a review.

The first choice group of psychotropic agents in schizophrenia is neuroleptics. However, this treatment is not effective in all patients and with every symptom. We summarize papers published on the role of antiepileptic drugs in treatment-resistant schizophrenia. We have searched the computer database system MEDLINE for relevant articles including reviews, reports of drug studies and case histories. Antiepileptic drugs can change symptoms of schizophrenia by their action on GABA-ergic neurotransmission or via anti-glutamatergic mechanisms. High doses of adjunctive benzodiazepines reduce positive symptoms, anxiety, and agitation. Carbamazepine is effective in affective symptoms of schizophrenia and influences violent behavior in psychotic patients. Its anti-kindling action may represent a promising treatment strategy for some patients with chronic course of schizophrenia. Valproate treatment leads to a decrease in positive symptoms as well as hostility. Lamotrigine is expected to influence the positive, negative, affective, and cognitive symptoms of schizophrenia. New antiepileptics (e.g., gabapentin, oxcarbazepine, topiramate, vigabatrin) present a promise as potential adjuncts to neuroleptic treatment in resistant symptoms of schizophrenia.     

Laser angioplasty: a new approach in the treatment of iliac occlusion

Laser thermal angioplasty is a new technique. The longest follow-up is 3 years. It is used increasingly for the treatment of atheromatous disease of the femoropopliteal segment. The authors describe a case of successful recanalization of a completely occluded left external iliac artery using laser thermal angioplasty. The artery was approached through a left femoral dissection. The patient was discharged from the hospital on postoperative day 4 without claudication. The present indications and potential benefits and complications of this procedure are discussed.     

Human cell-mediated immune responses to antigenic fractions of Salmonella typhi.

The proliferative responses of peripheral blood mononuclear cells of 10 subjects that had typhoid fever, and healthy volunteers without history of typhoid fever or immunization against disease, were analysed with antigen fractions from two protein extracts of Salmonella typhi. Fractions from each extract were separated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) electrophoresis, transferred to nitrocellulose filters by electroblotting and processed to obtain antigen-bearing nitrocellulose particles for use in lymphocyte cultures. Although the individual proliferative responses were heterogeneous we identified two main immunogenic regions of 29-32 10(3) MW and 45-56 x 10(3) MW for both extracts. Even though there was no one particular antigenic fraction capable of stimulating lymphocytes from all individuals with a previous history of typhoid fever, the combination of three fractions 29-32, 41-45, 63-71 x 10(3) MW could be stimulatory for cells of 90% of these individuals. Also, four subjects that did not respond to unfractionated antigens gave proliferative responses to several fractions of the same extract. We have identified the main immunogenic fractions of S. typhi that might play a role during typhoid infection and postinfection immunity, and merit further purification and characterization.     

Antihypertensive activity of redox derivatives of tryptophan

The essential amino acid, tryptophan, has been shown to lower blood pressure in rats when administered orally or intravenously. In order to potentially enhance this action, a brain-targeting chemical delivery system (CDS) approach was applied to this compound. The CDS is based on a dihydropyridine----pyridinium ion redox system, chemically analogous to the naturally occurring NADH----NAD+ system. The dihydropyridine moiety containing carrier is chemically attached to the amino group by an amide-type bonding while the carboxylic acid functionality is esterified to various alcohols. Physicochemical studies of the new derivatives were performed. The determined chromatographic Rm values indicate an increased lipophilicity for the CDSs compared to the parent compound. Oxidation stability studies performed on selected compounds using a ferricyanide-mediated method showed that the CDSs are oxidized to the respective quaternary salt forms. Activity studies performed in deoxycorticosterone acetate induced hypertensive rats, demonstrated that the delivery system for tryptophan reduced blood pressure more efficiently for a longer time than did the parent compound.