Nitric oxide synthase expression in the cerebral cortex of patients with epilepsy.

PURPOSE: Nitric oxide (NO), a short-lived radical synthesized from L-arginine by activation of the enzyme nitric oxide synthase (NOS), has been implicated in the pathophysiology of epilepsy by some investigators. However, the current data about NO and NOS in epilepsy are controversial and are derived only from animal models of epilepsy. In this study we investigated possible changes in NOS expression in the cerebral cortex of patients with epilepsy. METHODS: Qualitative and quantitative parameters of the immunolabeling pattern of the neuronal, endothelial, and inducible isoforms of NOS were analyzed in biopsy material obtained from patients with short and long seizure history and from patients without epilepsy. RESULTS: The comparative study showed that in the cerebral cortex of patients with epilepsy, particularly in those with a long seizure history, the number and labeling intensity of NOS-positive neurons increased, and that a subpopulation of nonpyramidal GABAergic neurons (type II NOS neurons) was responsible for this phenomenon. CONCLUSIONS: The fact that NOS upregulation is more evident in patients with a long seizure history suggests that this is a consequence of seizures, acting probably as an adaptative response to the sustained release of excitatory amino acids.

Monosomy 22 with humoral immunodeficiency: is there an immunoglobulin chain deficit?

The cytogenetic analysis of a patient with selective deficit of IgA and decrease in IgM, IgE, and IgG is presented. Using trypsin-Giemsa banding the karyotype showed monosomy 22 (45,XX,-22). The interest of this case lies in the rarity of the illness and in the association of monosomy 22 with hypogammaglobulinaemia and selective deficit of IgA, particularly as this chromosome is known to contain genes coding for immunoglobulin chains.