[ECT: from neuronal plasticity to mechanisms underlying antidepressant medication effect]. / ECT: de la neuroplasticité aux mécanismes d'action.

INTRODUCTION: Electroconvulsive therapy (ECT) is one of the most effective treatments for depression. Although it has been used for over 60 years, the basis for its therapeutic effect is still unknown. Structural plasticity within the nervous system such as neurogenesis or mossy fiber sprouting could be involved in the mechanisms underlying the antidepressant effect of several pharmacological antidepressants. But what is the mechanism underlying ECT? LITERATURE FINDINGS: Several methodological issues using magnetic resonance spectroscopy for humans and rats found changes in neuronal metabolism during ECT. The levels of N-Acetyl-Aspartate, an amino acid exclusively located in neurons, are increased after ECT; choline, which is believed to represent membrane turn-over, increases as well. These results are in good agreement with ECT induced structural plasticity. Electroconvulsive seizures (ECS), an animal model of ECT, can enhance neurogenesis, particularly in the hippocampal dentate gyrus. A series of seizures increases neurogenesis more than a single shock. In the glucocorticoid paradigm of depression, ECS can increase hippocampal neurogenesis. This suggests that induction of neurogenesis might be implicated in the antidepressant mechanism of ECT. DISCUSSION: As suggested by previous studies, Brain Derived Neurotrophic Factor (BDNF) is supposed to play a critical role in the action of antidepressants through neuronal plasticity. ECS increases the expression of BDNF. The BDNF gene has four differentially regulated promoters that generate four transcript forms. Studying the regulation of these transcript forms by diverse classes of antidepressant therapeutics, including ECS, suggests that diverse signalling mechanisms may be recruited to regulate BDNF transcripts. Moreover, for ECS, these signalling mechanisms seem to differ from those recruited by excitotoxic cell death phenomena, such as neuronal damage or epileptic seizure models. CONCLUSION: These results indicate the participation of neuronal plasticity to help account for the antidepressant effect of ECT. However, this relationship is currently not clearly defined, particularly in terms of causality, and will require future studies to unravel it.

[Executive and amnestic functions of a group of first-degree relatives of schizophrenic patients]. / Fonctions exécutives et mnésiques d'un groupe d'apparentés de premier degré de patients schizophrènes.

Several lines of evidence seem to indicate that some neurocognitive measures could be phenotypic markers of predisposition to schizophrenia. The aim of this study was to investigate 21 patients with schizophrenia, 51 of their first-degree relatives and 46 nonpsychiatric controls, with a series of tests known to be sensitive to prefrontal cortical damage--the Trail Making Test, part B (TMT B), the Wisconsin Card Sorting Test (WCST) and a verbal fluency test (VFT)- and/or sensitive to temporo-hippocampic dysfunctions: verbal and visual memory and verbal learning tests from the Wechsler Memory Scale-Revised (Wechsler, 1987). Since parents and siblings share on average 50% of their genes with the schizophrenic proband, firstly we predicted that the first-degree relatives' performance would be at an intermediate level between patients and control subjects and secondly, we expected that a higher proportion of relatives than of control subjects would be impaired. The patients demonstrated deviant patterns of neuropsychological performance on the three tests sensitive to frontal dysfunctions and on most of the memory and learning tests. In the relative group, performance on the TMT B, VFT, immediate verbal recall and verbal learning was at an intermediate level between both other groups and significantly impaired compared to control subjects. However, the relative group did not differ from the control group on the WCST, immediate visual recall, and delayed verbal and visual recalls. Furthermore, compared to the control group, the percentages of patients and relatives who scored one standard deviation below the mean control group were significantly higher for the VFT and immediate verbal recall scores. Among all the tests studied, the verbal fluency and the immediate verbal recall appeared to be valuable phenotypic markers of schizophrenia since: (i) their mean scores were poorer in the patient and in the relative groups, (ii) the percentages of patients and relatives with poor performance were higher than the percentage of controls, (iii) these deficits were not due to poorer general intellectual abilities in the relative group, (iv) these deficits did not correlate with anxiety or depression scores.

Isolation of the elusive pig islet.

This study describes a procedure for large scale isolation of swine islets. The reported results are from 15 consecutive isolations. The glands were removed from live animals with no warm ischemia, and the pancreata were digested by a modification of the automated method for human islet isolation. It was possible to separate an average of 690,000 +/- 279,429 islets per pancreas corresponding to 10,360 +/- 4034 islets per gram of pancreas with a volume of 714 +/- 480 mm3. After purification the recovery was 255,000 +/- 32,407 islets corresponding to 4,000 +/- 567 islets per gram of pancreas. Purity of the final preparation was 80% to 95% islets. Insulin content resulted in an average of 146.8 +/- 78 U before purification and 71 +/- 53 U after purification. After a 10 mm3 aliquot of the final preparation was transplanted under the renal subcapsular space of seven nude mice with diabetes, normoglycemia occurred in six of the mice. Thirty days after transplantation, nephrectomy of the kidneys bearing the grafts produced a rapid return to the diabetic state in all cases. This method makes it possible to provide large numbers of intact swine islets for preliminary studies of prevention of the rejection of pig islet xenograft by immunoalteration and immunoisolation procedures.

Swine islet isolation and transplantation.

An isolation procedure for large scale isolation of swine islets is described. The results from 15 consecutive isolations are reported. The glands were excised from heart beating animals with no warm ischemia time. The pancreases were digested by a modification of the automated method for human islet isolation. It was possible to separate an average of 690,000 +/- 279,429 islets per pancreas corresponding to 10,360 +/- 4034 islets for gram of pancreas with a volume of 714 +/- 480 mm3. After purification the recovery was 255,000 +/- 32,407 islets corresponding to 4,000 +/- 567 islets per gram of pancreas. Purity of the final preparation was 80-95% islets. Insulin content resulted in an average of 146.8 +/- 78 U before purification and 71 +/- 53 after purification. After transplantation of an aliquot of the final preparation in diabetic nude mice normoglycemia occurred in six mice. 30 days after transplantation nephrectomy of the kidneys bearing the grafts produced a rapid return to the diabetic state in all cases.

Selection of donors significantly improves pig islet isolation yield.

The purpose of the present study was to test the influence of donor age on islet isolation yield in swines. Large White pigs of 10 months (group 1, n = 10) and 2-3 years (group 2, n = 5) were used. A modification of the automated method for human islet isolation was used for pig islet separation. After ductal injection of a collagenase solution (Seromed, type C-1000) the islets were separated through a continuous digestion process. In group 1 it was possible to obtain an average of 636,100 islets (volume = 476.1 mm3, insulin content = 101.4 Units). In group 2 the average total islet number was 799,800 representing a volume of 1190.6 mm3 (Insulin content 210 Units). Total islet number was not significantly different in the two groups, however when islet volume and total insulin content were considered, older animals allowed a significantly higher yield (P less than 0.01 for volume and P less than 0.05 for insulin content). These findings indicate that it is possible to separate large number of pig islets from both young (10 months) and older (2-3 years) animals and that selection of donor pigs will improve islet isolation yield. These results may be of assistance in the definition of requirements for more effective islet isolation in swines.

Lithiasis inside a blind-ending branch of a trifid ureter.

A case of lithiasis inside a blind-ending branch of a trifid ureter is presented. This is a very uncommon anomaly and its association with lithiasis is not previously reported. The diagnosis was made by means of excretory urography followed by computed tomography (CT). The embryology, classification, and clinical aspects of such malformation are discussed.

Colonic duplication in an adult.

A case of colonic duplication that was diagnosed radiologically in an adult is reported. A long duplicated segment below the normal transverse colon, with a wide anastomosis at the hepatic flexure level, was observed on barium enema. The rarity of this anomaly unassociated with other malformations is emphasized.

[Several critical aspects of the value of peripheral markers in depression (TRH test and dexamethasone depression)]. / Quelques aspects critiques sur la valeur des marqueurs périphériques dans la dépression (TRH test et freination à la dexaméthasone).

Studies of depression carried out for over 10 years have led to the discovery of biological tracers for depression. The authors have performed numerous TRH and dexamethasone tests and in their opinion, the present enthusiasm for these tests should be tempered. In several aspects the various values attributed to them seem to be questionable. Owing to the difficulty in codifying these tests, the authors question their diagnostic, pronostic, therapeutic and predictive values. The authors' own experience as well as the evolution of the publications throughout the world have been taken into consideration. Finally, the problem of interferences and the doubtful specificity of endocrine tests for depression have been dealt with.

[Neurological complications of tricyclic antidepressive agents]. / Complications neurologiques des antidépresseurs tricycliques.

The tricyclics are antidepressive drugs in widest use today. They are one of the most effective of the psychotropic agents and would be used more often if it was not for the complications. In this article we consider the neurological stimulation that results in undesirable cardio-vascular responses that are the main side-effects of these drugs. First, a brief statement is made about the action of the antidepressive drugs on the synapses for both their therapeutic effects and their side-effects are produced at this level. Despite the many patterns of complications that can occur, it is important to remember that these drugs are still very useful in managing depression and they should be the treatment of choice in depressive syndromes.