Effect of pyridoxine on mice gastric ulcers and brain catecholamines after an immobilization stress

Fifty adult female Swiss albino mice were injected with either 1.11 mg/kg body weight pyridoxine or saline, subsequently they were all submitted to an immobilization stress with a complete fast for 17 h. At the end of this period, the animals were sacrificed, the gastric mucosa was dissected for ulcer count, and brain noradrenaline, dopamine and serotonin were determined by liquid chromatography. In addition, 26 nonstressed mice were used as controls, 16 of them being fed at libitum and 10 submitted to the same fasting period as the first two groups. In the stressed animals, the average number of gastric ulcers per mouse was twice as large in the saline-treated group than in the pyridoxine-treated group (p < 0.05). With a single exception, no ulcer was found in the non stressed controls. Brain norepinephrine content was almost identical in fasting controls and in stressed mice treated with pyridoxine; in the stressed animals treated with saline, the average norepinephrine content was higher by 15% and in the fed controls lower by 11% than in the two preceding groups. Pyridoxine treatment entailed a very significant reduction (p < 0.002) of norepinephrine variability, mainly due to the absence of high values (> or = 750 ng/g of fresh brain) which occurred only in the saline-treated group. Similar results were yielded for brain dopamine. No variations were observed for brain serotonin. These results suggest the antistress effect of pyridoxine.

Tissue and blood magnesium levels in spontaneously hypertensive rats, at rest and in stressful conditions

Magnesium (Mg) levels were measured by flame atomic absorption spectrophotometry in the blood (plasma, erythrocytes) and soft tissues (liver, brain, heart, aorta, kidneys, adrenals, spleen, thymus) of adult spontaneously hypertensive rats (SHR) and their normotensive controls, Wistar Kyoto (WKY). In experiment 1, Mg determinations were performed on eight animals of each strain at rest. Mg levels were lower in brain (P less than or equal to 0.05), kidneys (P less than or equal to 2.10(-4] and erythrocytes P less than or equal to 0.01) in SHR than in WKY rats. Tissue water content was the same in the two strains. These results suggest the occurrence of lower intracellular Mg levels in SHR than in WKY. In experiment 2, 15 SHR and 15 WKY were submitted either to acute (1 d) or subacute (22 d) stresses or reared in restful conditions. Acute stress induced important Mg shifts leading to a decreased difference between SHR and WKY in most tissues and to an increased and more significant difference (P less than or equal to 0.01) in spleen and plasma Mg levels. Subacute stress was milder and had little effect. It is concluded that the results of experiment 1 cannot be attributed to the greater sensitivity of SHR to laboratory manipulations. When compared with previously published data our results nevertheless suggest an association between stress sensitivity and genetic factors regulating Mg metabolism.

Landau-Kleffner syndrome: a pharmacologic study of five cases

Five children with Landau-Kleffner syndrome (epilepsy, acquired aphasia, and continuous spike-wave discharges during sleep), were treated with antiepileptic drugs (AEDs), sleep-modifying drugs, and corticosteroids. The pharmacologic profiles differed from those observed in focal epilepsies, resembling instead those of certain generalized epilepsies, such as West or Lennox-Gastaut syndromes. Phenobarbital (PB), carbamazepine (CBZ), and phenytoin (PHT) were ineffective or worsened the EEG and neuropsychological symptoms, whereas valproate (VPA), ethosuximide (ESM), and benzodiazepines were partially or transiently efficacious. Dextroamphetamine produced a dramatic but transient improvement in waking and sleep EEG in one of two children; aphasia did not change. Corticosteroid treatment resulted in improved speech, suppression of seizures, and normalization of the EEG in three of three children. Our own experience and data from the literature suggest that corticosteroids should be given in high doses as soon as the diagnosis is firmly established and should be continued in maintenance dose for several months or years to avoid escape. Early diagnosis, before mutism or global deterioration develops, appears to be essential for effective therapy with minimal neuropsychological sequelae.

Cerebral glucose utilization during sleep in Landau-Kleffner syndrome: a PET study

Three right-handed male children (aged 5, 6, and 11 years) with signs, symptoms and/or history of the syndrome of acquired aphasia-epilepsy (Landau-Kleffner syndrome) were studied during drug-induced, electroencephalographically (EEG)-monitored sleep by positron-emission tomography (PET) and the [18F]fluorodeoxyglucose (FDG) method. Our data demonstrate that in Landau-Kleffner syndrome, cerebral glucose utilization is not normal during sleep. The metabolic pattern varied between the children but the metabolic disturbances always predominated over the temporal lobes. They were right-sided, left-sided, or bilateral. In the two first patients, EEG recordings showed continuous spike-and-wave discharges during sleep and a right-greater-than-left asymmetry was observed in temporal areas. In patient 1, the asymmetry was associated with a relative increase of glucose utilization of the right posterior temporal region. In patient 2, the glucose utilization was relatively decreased in the left anterotemporal and left perisylvian regions. In patient 3, the sleep EEG showed no discharge and no significant asymmetry was observed; however, glucose utilization of both temporal lobes was decreased. Lower metabolic rates in subcortical structures than in cortex were also noted in the three children. This metabolic pattern may be related to the maturation of the central nervous system (CNS).

Landau-Kleffner syndrome: a clinical and EEG study of five cases

In five children with normal initial psychomotor development, a Landau-Kleffner syndrome appeared at age 3-7 years. No neuroanatomic lesions were noted. Aphasia and hyperkinesia were isolated in three patients and associated with global regression of higher cortical functions in one patient. Massive intellectual deterioration and psychotic behavior were associated with transient aphasia in one patient. The epilepsy (focal motor and generalized tonic-clonic seizures, subclinical EEG focal seizures during sleep, and atypical absences) always regressed spontaneously or with antiepileptic drug (AED) treatment. The EEG in waking patients showed focal and generalized spike-wave discharges on a normal background rhythm. Discharge topography and pattern changed frequently. During sleep, discharges always increased. At some time during syndrome development, all patients had bilateral spike-waves for greater than 85% of the sleep period, while at other times the discharges were discontinuous or continuous but focal or unilaterally hemispheric. Discharge topography and abundance changed from night to night. The abnormal EEG and the impaired higher functions developed and regressed together, but not with strict temporal correlation. Our own experience suggests that the Landau-Kleffner syndrome and epilepsy with continuous spike-wave activity in slow-wave sleep cannot be clearly differentiated. They may be different points on the spectrum of a single syndrome.

A plasma factor inhibiting erythrocyte magnesium efflux

When incubated at 37 degrees C for 5 h in a magnesium- and calcium-free phosphate buffer solution (PBS), rat and mouse erythrocytes lose 30-40% of their Mg content. However, no Mg loss is observed if these erythrocytes are incubated in their own plasma. In order to investigate this phenomenon, murine erythrocytes were incubated in PBS, in human and murine blood plasmas, and fetal calf serum diluted in PBS (1/4), and in PBS supplemented with MgCl2, CaCl2, and crystallized plasma proteins at concentrations equal to those obtained in plasma/PBS solutions. Erythrocyte Mg efflux was significantly inhibited (P = 10(-8] by diluted human and rat plasmas but the time course of this inhibition was different with these two kinds of plasmas (P = 10(-4]. Mouse plasma and fetal calf serum also entailed a significant inhibition of Mg efflux, while the addition of Mg, Ca, and purified plasma proteins in the incubation medium had little effect. Blood plasma thus contains a factor inhibiting Mg efflux from murine erythrocytes and this effect is not explained by its content of magnesium, calcium, and proteins.

Moclobemide versus clomipramine in the treatment of depression: a double-blind multicentre study in Belgium

Moclobemide and clomipramine were compared for efficacy, tolerance and safety in 63 mixed endogenous and nonendogenous depressed patients. Treatment was given for at least 4 weeks in a double-blind, randomized, parallel-group design. The mean Hamilton Rating Scale for Depression score decreased gradually during treatment with no differences between groups. Two patients on clomipramine and none on moclobemide were withdrawn for lack of efficacy, and poor tolerance caused 3 patients on moclobemide and 7 on clomipramine to stop treatment prematurely. Patients with endogenous depression responded better to clomipramine, whereas nonendogenous disorders did better on moclobemide. Adverse events were more frequent in the clomipramine group and more of these were severe or very severe than for moclobemide. Thus, although no significant difference in efficacy was seen, moclobemide appeared to be tolerated better than clomipramine. The numbers were small, however, and many patients received concomitant medication, and the results are therefore difficult to interpret.

Blood and tissue zinc levels in spontaneously hypertensive rats

Zinc (Zn) determinations were performed on blood plasma and red cells, liver, heart, adrenals, and spleen of spontaneously hypertensive (SHR) and control normotensive (WKY) male rats, 20 weeks of age. SHR revealed higher red cell (p = 2 x 10(-5)) and heart (p = 0.007) Zn levels than WKY rats. The water content of organs was the same in the two strains. When compared with published data, these results suggest an association between high cell Zn levels and hypertension, the meaning of which is briefly discussed.

Cerebral glucose utilization during sleep-wake cycle in man determined by positron emission tomography and [18F]2-fluoro-2-deoxy-D-glucose method

Using the [18F]fluorodeoxyglucose method and positron emission tomography, we studied cerebral glucose utilization during sleep and wakefulness in 11 young normal subjects. Each of them was studied at least thrice: during wakefulness, slow wave sleep (SWS) and rapid eye movement sleep (REMS), at 1 week intervals. Four stage 3-4 SWS and 4 REMS fulfilled the steady state conditions of the model. The control population consisted of 9 normal age-matched subjects studied twice during wakefulness at, at least, 1 week intervals. Under these conditions, the average difference between the first and the second cerebral glucose metabolic rates (CMRGlu was: -7.91 +/- 15.46%, which does not differ significantly from zero (P = 0.13). During SWS, a significant decrease in CMRGlu was observed as compared to wakefulness (mean difference: -43.80 +/- 14.10%, P less than 0.01). All brain regions were equally affected but thalamic nuclei had significantly lower glucose utilization than the average cortex. During REMS, the CMRGlu were as high as during wakefulness (mean difference: 4.30 +/- 7.40%, P = 0.35). The metabolic pattern during REMS appeared more heterogeneous than at wake. An activation of left temporal and occipital areas is suggested. It is hypothetized that energy requirements for maintaining membrane polarity are reduced during SWS because of a decreased rate of synaptic events. During REMS, cerebral glucose utilization is similar to that of wakefulness, presumably because of reactivated neurotransmission and increased need for ion gradients maintenance.

Reproducibility of cerebral glucose utilization measured by PET and the [18F]-2-fluoro-2-deoxy-d-glucose method in resting, healthy human subjects

The stability of cerebral glucose utilization was examined in nine right-handed, healthy men (age, 24.88 +/- 2.93 years) using positron emission tomography (PET) and the [18F]-fluorodeoxglucose (FDG) method. Each study was run twice at intervals of 1-12 weeks with the subject at rest. The average cerebral metabolic rate for glucose (CMRGlu) was 5.40 +/- 0.71 mg/100 g per min (coefficient of variance, 13.08). The average intraindividual variation of CMRGlu was 7.91% +/- 15.46% (P = 0.13). Metabolic indices (MI: regional/mean cortical CMRGlu) were used to determine the regional cerebral metabolic distribution. The interindividual (coefficient of variance, 7.13) and intraindividual variabilities (average variation, -0.12% +/- 8.76%) of MI were smaller than those of metabolic rates. No reproducible significant asymmetry was observed. The FDG method used with subjects at rest thus yields low intraindividual variability of both cerebral glucose consumption and regional metabolic distribution, even at an interval of several weeks. Cerebral glucose utilization measured under such conditions may act as a reliable reference for determination of the influences of physiological (activation), pharmacological or pathological processes on cerebral glucose metabolism.

Non-invasive methods to study drug disposition: positron emission tomography. Detection and quantification of brain receptors in man

Positron emission tomography (PET) has been used mostly for the study of brain blood flow and metabolism in normal controls and in a variety of neurological and psychiatric conditions. With the appropriate radiotracers, PET also allows non-invasive imaging and quantification of a growing list of neuroreceptors, the target of most psychotropic drugs. For example, 11C-carfentanil and 11C-diprenorphine, two potent opiate ligands, have been used to label opiate receptors in vivo in man. Methods have been developed to quantify receptor studies with PET in terms of receptor density and affinity. PET is a unique tool that now allows measurement of receptor occupancy in vivo and could be used by the pharmacologist to optimize drug treatment.

Controlled comparison of buspirone and oxazepam in generalized anxiety

The anxiolytic activity, the tolerance, and the withdrawal symptoms of buspirone and oxazepam were compared in two groups of 14 and 12 outpatients, respectively, suffering from generalized anxiety in a double-blind study with random allocation of patients. The 6-week active period was preceded and followed by 1 and 2 weeks on placebo, respectively. Clinical assessments were performed before and after the predrug placebo period and every 2 weeks thereafter and included Hamilton anxiety and depression scales and AMDP anxiety subscale. The initial daily dose was 15 mg buspirone or 45 mg oxazepam in 3 intakes and the mean final daily doses were 22.2 and 55.8 mg, respectively. Results showed a slower anxiolytic activity of buspirone compared to oxazepam with less improvement after 2 weeks of treatment. The rebound anxiety following abrupt discontinuation of the drug and the level of side effects did not significantly differ between the two compounds.

Quantitative analysis of 18/FDG-PET in the presurgical evaluation of patients suffering from refractory partial epilepsy. Comparison with CT, MRI, and combined subdural and depth. EEG

CT, MRI, 18/FDG-PET and Depth. EEG, performed with subdural and depth electrodes were part of the presurgical evaluation in 22 patients. Statistical analysis of 18/FDG-PET was performed to compare cerebral utilization of glucose to that of normal age matched controls. The findings of CT, MRI, and quantitative analysis of PET are compared with those of ictal Depth. EEG. A positive correlation between CT and Depth. EEG was obtained in 23% of the patients and between MRI and Depth. EEG. in 50%. For both imaging techniques a negative correlation was found in 5%. Regional abnormalities were found with quantified PET in 95% of the patients and were concordant with Depth. EEG. for side of onset in 77% of the patients and for lobe of onset in 59%. A possibly false localising PET result for lobe of onset was obtained in 8 patients (36%). Limitations of PET were most apparent in patients with regional mesiolimbic or bilateral seizure onset. A favourable outcome of surgery was associated usually with positive convergence of both methods. PET may be a valuable contribution to the research and management of partial complex epilepsy, but at present cannot be considered a reliable alternative to invasive EEG methods in patients without clear unilateral focus localization on surface EEG.

Metabolic and circulatory evaluation of cerebral ischemic accident in humans by positron emission tomography: a pilot study with almitrine-raubasine

Positron emission tomography and oxygen-15 were used to evaluate the effect of almitrine-raubasine combination on cerebral blood flow and oxidative metabolism in patients with cerebral ischemia. In five patients aged between 58 and 74 years, with a cerebral ischemic accident in the territory of the middle cerebral artery, blood flow rate, oxygen metabolic rate, and cerebral oxygen extraction were measured before and after a 90-min intravenous perfusion of almitrine bismesilate 15 mg and raubasine 5 mg. Investigations were performed from day 2 to day 7 after stroke occurred. One patient showed evidence of initial relative luxury perfusion, the degree of which was reduced by such combined treatment. The other four patients had a focal reduction in cerebral blood flow and oxygen consumption prior to treatment. The statistical analysis of three cerebral areas (epicenter of lesion, anterior and posterior juxtalesional areas, and homologous heterolateral areas) showed a 3.6% increase in oxygen metabolic rate at the epicenter, when both hemispheres were taken together, and a significant increase in cerebral blood flow in all three areas (3% on the healthy hemisphere, 13% on the injured hemisphere). These changes were greater in some patients than in others. This suggests that heterogeneity of drug responses may correspond to the heterogeneity of the initial status.

Correlation between total and free magnesium levels in human red blood cells. Influence of HLA antigens

Total and free magnesium contents were determined by atomic absorption spectrophotometry and 31P nuclear magnetic resonance on red blood cells of healthy blood donors of known HLA groups. A statistically significant correlation was found between free and total magnesium contents (r = 0.67, P less than 0.02). The previously described low total magnesium contents in HLA-B35+ subjects were associated with low free Mg2+ contents. Therefore, total and free magnesium and HLA-associated genetic factors are closely related.

Positron emission tomography in degenerative dementias

Positron emission tomography demonstrates different abnormalities of cerebral metabolism or characteristic disturbances of neurotransmission systems in "cortical" and "subcortical" dementias. Those patterns may reflect the underlying anatomopathology, but may also give clues to the pathophysiology of a disease and its symptoms.

[Electroconvulsive therapy and its mechanism of action]

Electroconvulsive therapy (ECT) is known as an effective treatment for some depressive disorders. Nevertheless ECT continues to be a subject of controversy. The absence of a unifying theory for its mechanisms of action explains the mistrust about ECT. The aim of this article is to review the literature about ECT and to propose a synthesis concerning its mechanisms of action. At the present time, the most reliable hypothesis suggests selective activations of central serotonergic and dopaminergic systems on the one hand, and a direct stimulation of the neuroendocrine neurons on the other hand.

Blunted response of growth hormone to clonidine and apomorphine in endogenous depression

We measured the growth hormone (GH) response to clonidine (an alpha-2-adrenergic agonist) and to apomorphine (a dopaminergic agonist) in 15 major endogenous and 15 minor depressive in-patients matched for gender and age. Results showed a significantly smaller GH response in the major depressives to both clonidine (P less than 0.01) and apomorphine (P less than 0.001). No significant difference existed between the two groups with regard to changes in blood pressure and pulse rate during either test. While major depressives showed a trend toward smaller sedative side-effects than minor depressives after clonidine, they showed significantly smaller sedative and gastro-intestinal side-effects after apomorphine. No significant correlation was present either in the major depressive or in the minor depressive group between the GH responses following clonidine and apomorphine challenges. These results support the hypothesis of both noradrenergic and dopaminergic neurotransmitter disturbances in major depression, with individual variability with regard to those biochemical anomalies.