The insular lobe of Reil--its anatamico-functional, behavioural and neuropsychiatric attributes in humans--a review.

There is considerable clinical and experimental research to explore the anatamico-functional correlations of the limbic lobe to establish its relevance in modern neuroscience. The insula being a pivotal structure in the concept of the greater limbic lobe, we have attempted to highlight in this review the topographical anatomy and development, the remarkable heterogeneity of the insular cortical architecture, the widespread multifaceted spectrum of functional connectivity patterns and how this is translated to its behavioural specialisation in humans. The insula serves as an intergration cortex for multimodal convergence of distributed neural networks such as the somesthetic-limbic, insulo-limbic, insulo-orbito-temporal and the prefrontal-striato-pallidal-basal forebrain. This provides the conceptual framework to facilitate functional and clinical considerations relevant to the various behavioural and neuropsychiatric disorders outlined in this review. The functional role of the insula in these disorders with particular reference to the current functional neuroimaging data has been also reviewed in this article.     

The distribution of factor XIIIa-positive cells in the human fetus and placenta

Summary Immunohistochemical staining for factor XIIIa, a transglutaminase, revealed a variety of positively stained cells in human fetal tissues. Factor XIIIa-positive cells were most numerous in the dermis and connective tissues. Numerous large, stellate cells in placental villi, decidua, and chorionic membranes also expressed factor XIIIa at 7–9 weeks gestational age, before the onset of fetal hematopoiesis. There was heterogeneity in the staining for factor XIIIa in the early and late fetal tissues, in both rounded and in dendritic cells. In preparations of consecutive sections and in double-labelling experiments, some cells expressed both factor XIIIa and certain monocyte markers and were identified in close association with blood vessels and lymphoid organs in the late fetus and in the placental villi at the end of gestation. Other rounded and dendritic cells expressed factor XIIIa but not monocyte markers, and were found in adult and fetal connective tissues at all gestational ages. These results suggest that there are two factor XIIIa-positive cell populations. One population is present at all developmental stages, does not express monocyte markers, and probably differentiates in situ from primitive mesenchyme. The other population appears mainly after the onset of fetal hematopoiesis, coexpresses some monocyte markers, is HLA-DR positive and may be capable of antigen presentation.Presented at the U.S.-Canadian Academy of Pathology Meeting, March 1991 (Trimble et al. 1991)     

Psychosis following temporal lobe surgery: a report of six cases.

Six consecutive patients who had had temporal lobe surgery for epilepsy, and been referred for psychiatric assessment of psychotic symptoms, are reported. Their symptoms (a delusional depression, four schizophrenia-like illnesses, and a case of Capgras' syndrome) are discussed in relation to the possible role of their operations, all of which were on the right hemisphere.     

Elevated frontal cerebral blood flow in Gilles de la Tourette syndrome: a 99Tcm-HMPAO SPECT study.

Case reports, numerous brain imaging studies, and certain disease states suggest that the orbital frontal cortex and the striatum are dysfunctional in obsessive-compulsive disorder (OCD). Interest has also grown recently concerning the genetic, neuroanatomic, and clinical links between OCD, chronic motor tics, and Gilles de la Tourette Syndrome (GTS). To test the hypothesis of possible orbito-frontal/basal ganglia dysfunction in GTS, similar to OCD, we studied 20 unmedicated GTS subjects, 10 of whom also had comorbid OCD (GTS/OCD), and 8 control subjects. The subjects were examined with high-resolution single photon emission computed tomography (SPECT) and the labeled regional cerebral blood flow (rCBF) ligand technetium-99m-d,l-hexamethyl-propylene amine oxime (99Tcm-HMPAO). As a group, GTS subjects showed significantly elevated right frontal/visual cortex activity (mean = 0.879, SD = 0.107) compared with control subjects (mean = 0.798, SD = 0.049). A subanalysis comparing simple GTS versus GTS with comorbid OCD failed to reveal significant differences in regional flow.     

ENDOTHELIAL DYSFUNCTION EXACERBATES THE IMPAIRMENT OF RELAXATION BY LYSOPHOSPHATIDYLCHOLINE IN PORCINE CORONARY ARTERY

1. Current evidence suggests that lysophosphatidylcholine (LPC), a component found in oxidized low-density lipoprotein (Ox-LDL), inhibits endothelium-dependent relaxation (EDR) mediated by endothelium-derived relaxing factor (EDRF) and endothelium-derived hyperpolarizing factor (EDHF). An objective of the present study was to characterize the roles of the different elements of EDR in LPC-induced impairment within the porcine coronary artery. Concomitantly, we sought to determine whether impairment of one component of EDR would increase the sensitivity of the endothelium to LPC. 2. Bradykini. (0.1 nmol/L-0.3 μmol/L) relaxed U46619 (30 nmol/L)-precontracted porcine coronary artery rings in a concentration-dependent manner. A reduction in the bradykinin-elicited response was observed in N^G-nitro-L-arginine methyl ester (L-NAME; 300 μmol/L)- and ouabain (50 μmol/L)-treated rings. Pretreatment with LPC (20 μmol/L), which on its own had no effect on normal endothelial relaxation, resulted in further inhibition of EDRF- and EDHF-induced relaxations. 3. Our results demonstrate that EDRF and EDHF are the primary mediators of EDR in the porcine coronary artery. Our data also show that while a low concentration of LPC (20 μmol/L) does not impair EDR, it can evoke vascular dysfunction following blockade of either the effects of EDRF or EDHF. Therefore, these data suggest that the partially damaged vascular endothelium could be more sensitive to threshold levels of this atherogenic phospholipid.