In situ beta-irradiation of a brain arteriovenous malformation model.

Background And Purpose: The treatment of large brain arteriovenous malformations (BAVMs) is challenging, and embolization alone is seldom curative. The study goal is to enhance the efficacy of arteriovenous malformation embolization by adding a beta-emitting isotope to the embolic agent.

Methods: The pig rete mirabile was used as a BAVM model.

Production of radioactive particles for endovascular therapeutic interventions.

Recanalization is a common phenomenon that decreases the efficacy of embolization procedures. It can be inhibited by beta-radiation. Two novel ways of producing radioactive particles are described, by neutron beam irradiation of gold-containing microspheres, or by using the 32P binding capacity of zirconium-containing microspheres.

Detection of diffuse abnormal perfusion in SPECT using a normal brain atlas.

Visual assessment, with significant inter- or intraobserver variability, is still the norm for the evaluation of Single Photon Emission Computerized Tomography (SPECT) cerebral perfusion studies. We present in this paper an automated method for screening SPECT studies to detect diffuse disseminated abnormalities based on a computerized atlas of normal regional cerebral blood flow (rCBF). To generate the atlas, a set of normal brain SPECT studies are registered together.

Comparison between olanzapine and haloperidol on procedural learning and the relationship with striatal D2 receptor occupancy in schizophrenia.

The striatum is known to play a primary role in procedural learning. In this study, the authors simultaneously assessed the effects of two antipsychotic drugs on procedural learning and on striatal dopamine (D2) receptor occupancy. Twenty-seven patients receiving either olanzapine or haloperidol as antipsychotic medication were assessed with the Computed Visual Tracking Task (CVTT) and Single Photon Emission Computed Tomography (SPECT) following the administration of Iodine 123-IBZM (123I-IBZM), a radioligand with a high affinity and specificity for the D2 receptors.

Alpha-[11C] methyl-L-tryptophan and glucose metabolism in patients with temporal lobe epilepsy.

Objective: To determine whether metabolism in the brain serotonergic system, including the kynurenine pathway, is involved in temporal lobe epilepsy (TLE).

Methods: The authors studied 14 patients with intractable TLE by PET using alpha-[11C] methyl-L-tryptophan (alpha-MTrp) and 2-[18F]-fluoro-deoxy-glucose (FDG) and compared results with 21 healthy control subjects who had alpha-MTrp PET studies. Seven patients had unilateral hippocampal atrophy (HA), and seven had normal hippocampal volumes (NV).

Cognitive deficits and striatal dopaminergic denervation in Parkinson's disease: a single photon emission computed tomography study using 123iodine-beta-CIT in patients on and off levodopa.

Cognitive deficits affecting executive (frontal) functions have been widely described in Parkinson's disease (PD). However, dopa therapies are generally ineffective at reversing these deficits, except for tasks involving a sharing of attention such as working memory or simultaneous processing tasks. The aim of this study was to assess the relation between the nigrostriatal dopaminergic denervation in PD, as measured by SPECT with (123)Iodine-beta-CIT and the cognitive deficits, as measured by a simultaneous processing task, which had already been shown to be sensitive to dopa treatment.

SPECT imaging of striatal pre- and postsynaptic dopaminergic status in restless legs syndrome with periodic leg movements in sleep.

Restless legs syndrome (RLS) is a common sleep-related disorder principally characterised by leg paresthesia associated with an irresistible urge to move. A majority of RLS patients experience periodic leg movements during sleep (PLMS) and wakefulness. Pharmacological evidence suggests that RLS-PLMS may be caused by a central nervous system dopaminergic (DA) dysfunction.

Lack of associations between occlusal and cephalometric measures, side imbalance in striatal D2 receptor binding, and sleep-related oromotor activities.

Aims: First, to evaluate possible orofacial morphologic differences between sleep bruxers and non-bruxers, and second, to determine possible correlations between morphologic factors and striatal D2 receptor expression in persons with sleep-related oromotor activities.

Methods: Twenty subjects were included in this study; half of them had polysomnographically confirmed oromotor values above the cutoff points for sleep bruxism. For all participants, 26 standard occlusal measures were recorded clinically and from dental study casts.

Double-blind, crossover, placebo-controlled trial of bromocriptine in patients with sleep bruxism.

This study was designed to assess the effects of bromocriptine, a dopamine D2 receptor agonist, on sleep bruxism. Seven otherwise healthy patients with severe and frequent sleep bruxism participated in this randomized, double-blind, placebo-controlled study. The study used a crossover design that included 2 weeks of active treatment or placebo with a washout period of 1 week.

Absence of correlation between amobarbital distribution as assessed with SPECT brain perfusion imaging and behavioral manifestations during the intracarotid amobarbital procedure (Wada test).

1. The IAP is used presurgically in patients with temporal lobe epilepsy to predict the effects on LTM and language of the planned temporal lobectomy. This prognosis presumes that a similar pattern of perfusion will result in anesthesia of the same cerebral regions in most patients.

Protein meals and postprandial thermogenesis.

In North America the consumption of meat far exceeds that of fish. Because the palatability of the food has been shown to influence the thermogenic response to feeding, a study was designed to compare the metabolic response to 195-g beef steak and 250-g cod fillet containing both 43 g of proteins in a first experiment and to 250 g of both nutrients in a second experiment. The subjects who participated in this study gave a higher rating of palatability (obtained on a 10-cm visual analog scale) when the beef steak (7.

Effects of the D2 receptor agonist bromocriptine on sleep bruxism: report of two single-patient clinical trials.

An altered dopamine receptor status has been associated with sleep bruxism. Evidence from a functional neuro-imaging study has implicated an abnormal side imbalance in striatal D2 receptor expression in its pathophysiology. To assess the significance of this finding, we studied the effects of short-term administration of the preferential dopamine D2 receptor agonist bromocriptine on sleep bruxism in a double-blind, placebo-controlled polysomnographic and neuro-imaging study with a single crossover design.

Comparative evaluation of [3H]WIN 35428 and [3H]GBR 12935 as markers of dopamine innervation density in brain.

WIN 35428 and GBR 12935, two uptake blocker ligands of the membrane transporter for dopamine (DA), were evaluated as quantitative markers of DA innervation density in CNS tissue. From alternate rat brain slices respectively processed for either light microscope or film autoradiography, counts of DA axon terminals (varicosities) labeled by uptake/storage of [3H]DA were matched with densitometric measurements of the specific binding of [3H]WIN 35428 and [3H]GBR 12935 in the same anatomical areas. The relation between the two parameters was examined in 1) the normal cingulate cortex; 2) the neostriatum severely DA-denervated by unilateral intramesencephalic injections of 6-hydroxydopamine; and 3) the neostriatum, partly DA-reinnervated by an intrastriatal graft of fetal mesencephalic neurons after prior 6-hydroxydopamine lesion.

Striatal D2 receptor binding in sleep bruxism: a controlled study with iodine-123-iodobenzamide and single-photon-emission computed tomography.

The neurochemical mechanisms underlying sleep bruxism are little understood at present. However, recent pharmacologic evidence suggests that the central dopaminergic system may be involved in the pathophysiology of sleep bruxism. This possibility was further assessed by means of functional neuroimaging of dopamine D2 receptors with single-photon-emission computed tomography (SPECT).

Interactions between postprandial thermogenesis, sensory stimulation of feeding, and hunger.

An early thermogenic response has been described following the ingestion of palatable food. This study was designed to investigate the possible relationship between this so-called cephalic response, the sensory stimulation of feeding, and the declining feeling of hunger as the meal progresses. O2 consumption, carbohydrate and lipid oxidation, as well as ratings of hunger were measured in four experimental situations in which the subjects, after overnight fast, ate either two small caramel cakes at one time or the same amount of calories divided in eight portions that were eaten at 10-min intervals.

Autosplenectomy in systemic lupus erythematosus.

Autosplenectomy in systemic lupus erythematosus (SLE) is associated with a high mortality rate due to Streptococcus pneumoniae sepsis. We describe 2 patients who developed autosplenectomy in the setting of an acute SLE exacerbation. Followup of both patients 12 and 5.

Early insulin and glucagon responses to different food items.

An early postprandial insulin release has previously been described when high carbohydrate meals are fed. The present investigation on humans shows that this response takes place not only with high carbohydrate (sugar pie) but also with high lipid (whipped cream) and protein (beef steak or fish fillet) meals, suggesting that it is caused by the palatability of the food rather than to its composition. This increment takes place at the very beginning of the meal and even if the period of feeding lasted 10 min, the response has disappeared at that time.

Evaluation of three transporter ligands as quantitative markers of serotonin innervation density in rat brain.

Direct counting of axon terminals (varicosities) labeled by uptake/storage of a tritiated monoamine provides a means to test radioligands of the corresponding membrane transporter as quantitative markers of regional monoamine innervation density in brain tissue. In autoradiographs from alternate rat brain slices, counts of [3H]5-HT-labeled axon terminals were matched with densitometric measurements of the specific binding of tritiated cyanoimipramine (CYI), citalopram (CITAL), and 6-nitroquipazine (6-NTQ), under conditions of hypo-, normo-, or hyper-5-HT innervation of the neostriatum. A total of 267 pairs of data were subjected to a multilevel analysis (iterative generalized least square procedure).

Quantification of the serotonin hyperinnervation in adult rat neostriatum after neonatal 6-hydroxydopamine lesion of nigral dopamine neurons.

Light microscope autoradiography after uptake and storage of tritiated serotonin (5-HT) in brain slices was used to count 5-HT axon terminals (varicosities) in the 5-HT-hyperinnervated neostriatum of adult rats subjected to neonatal 6-hydroxydopamine treatment and age-matched, normal controls. After correction for incomplete autoradiographic exposure and for section thickness, the results were expressed in millions of varicosities per mm3 of tissue. Control values ranged from 4.

Validation of the transporter ligand cyanoimipramine as a marker of serotonin innervation density in brain.

Unlabelled: Radiolabeled ligands of monoamine transporters have already been used to visualize cerebral monoamine innervation by tissue autoradiography and by PET or SPECT in vivo.

Methods: A sampling technique was developed to allow for both the autoradiographic counting of serotonin (5-HT) axonal varicosities, labeled by uptake and storage of [3H]5-HT, and the measurement of the binding of [3H]cyanoimipramine ([3H]CYI), a specific 5-HT transporter ligand, in adjacent slices of adult rat neostriatum. The experiments were conducted in normal, decreased (after 5,7-dihydroxytryptamine lesions in adults) or increased (after 6-hydroxydopamine lesions in neonates) states of neostriatal 5-HT innervation.

Hormonal dose-response to an adenosine receptor agonist.

The effect of various doses of i.p. injection of the adenosine receptor agonist (R)-phenylisopropyladenosine (R-PIA), ranging from nanomolar to micromolar concentrations, on plasma levels of free fatty acids, glucose, insulin, glucagon, ACTH, and corticosterone was examined in 200-g male rats.

Increase in T3 levels during hypocorticism in patients with chronic secondary adrenocortical insufficiency.

The clinical and biochemical manifestations of secondary adrenocortical insufficiency are not well defined in the medical literature. This study was designed to determine the clinical and laboratory features suggesting the diagnosis of adrenal insufficiency in 15 chronic ACTH deficiency patients during low and normal cortisol states. Except for fatigue and weakness, the characteristic clinical manifestations of primary adrenal insufficiency occurred rarely.

Reversible hypertriiodothyroninaemia due to adrenal insufficiency.

It is well known that an excess of glucocorticoids affects thyroid tests. The effect of adrenal deficiency on thyroid hormones is less well defined. We here describe the case of a 33-year-old woman with Cushing's disease who was cured by trans-sphenoidal surgery.