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Background Congestive heart failure is associated with decreased stimulated myocardial adenylate cyclase activity, increased G i -binding protein, attenuated parasympathetic tone, and increased modulation of β-adrenergic inotropic left ventricular stimulation by parasympathetic agonists. Despite these abnormalities, changes in the density or affinity of ventricular muscarinic receptors have not been demonstrated in patients. Methods and Results The density and affinity constants of myocardial muscarinic receptors were evaluated noninvasively by means of positron emission tomography with 11 C-MQNB (methylquinuclidinyl benzilate), a specific hydrophilic antagonist, in 20 patients with congestive heart failure due to idiopathic dilated cardiomyopathy (mean left ventricular ejection fraction, 22±9%) and compared with values in 12 normal subjects. The mean receptor concentration was significantly higher in patients than in control subjects ( B′ max , 34.5±8.9 versus 25±7.7 pmol/mL, P P r =.45, P Conclusions Congestive heart failure is associated with an upregulation of myocardial muscarinic receptors. This may be an adaptive mechanism to β-agonist stimulation and should increase the number of potential targets for pharmacological intervention.

The development of functional brain asymmetry during childhood is confirmed by changes in cerebral blood flow measured at rest using dynamic single photon emission computed tomography. Between 1 and 3 years of age, the blood flow shows a right hemispheric predominance, mainly due to the activity in the posterior associative area. Asymmetry shifts to the left after 3 years. The subsequent time course of changes appear to follow the emergence of functions localized initially on the right, but later on the left hemisphere (i.e. visuospatial and later language abilities). These findings support the hypothesis that, in man, the right hemisphere develops its functions earlier than the left.

The influence of the collimator on the contrast recovery of hyperfixation was studied using a dual-headed single photon emission computed tomography (SPECT) system with standard clinical acquisition parameters. Three parallel collimator sets and two fan beam collimator sets were tested with a Jaszczak phantom. The six spheres of the phantom were filled with /sup 99m/Tc, and four background levels were progressively obtained by adding radioactivity to the cylinder of the phantom, providing four hyperfixation levels. The effects of angular sampling and reconstruction filters have been tested. The statistical analysis was performed with analysis of variance (ANOVA). This study demonstrates the advantage of ultra-high resolution fan beam collimators for contrast recovery of hyperfixation with SPECT when using 64 projections over 360/spl deg/, in particular when the contrast is low. The authors also demonstrate that fan beam collimators permit smaller size hyperfixation detection.

Magnetic resonance imaging was used to determine total fat mass of patients with neuromuscular disorders, accounting for intramuscular fat. Nineteen boys aged 9 to 12 (eight with Duchenne muscular dystrophy, three with type II spinal muscular atrophy and eight control subjects) underwent whole-body magnetic resonance imaging examination and anthropometric measurements. Whole-body fat mass was deduced from automated analysis of images normalized by a reference signal. Intramuscular and subcutaneous fat masses were deduced from manual analysis of twelve reference slices. Affected children significantly differed from control subjects for higher total fat mass, mostly related to intramuscular fat mass. Shorter protocols validated from whole-body data were shown to be more accurate than fat mass estimation derived from anthropometric measurements.

Background In myotonic dystrophy (DM), striated muscle is involved in relation to the size of the DNA mutation. Smooth muscle may be similarly impaired at the level of the urinary and digestive apparatus and possibly at the level of small vessels, since microangiopathy has been described in the iris and digital capillaries. Our purpose was to study the function of the myocardial microvasculature in relation to the size of the mutation in DM patients without clinical cardiac involvement and with normal left ventricular dimensions and function and normal large coronary arteries. Methods and Results In 6 control subjects and 10 DM patients, we investigated the coronary blood flow reserve using positron emission tomography with 15 O-labeled water. Global and regional flow reserves were obtained from myocardial regions of interest manually drawn on a static FDG image encompassing, respectively, the whole left ventricle and the anterior, septal, and lateral walls. The DNA mutation size was determined on circulating lymphocytes in each DM patient. Compared with control subjects, DM patients had decreased global (2.39±0.39 versus 4.00±0.67, P =.00003) and regional (anterior, 2.39±0.64 versus 3.87±0.92, P =.002; septal, 2.60±0.48 versus 4.00±0.70, P =.0003; lateral, 2.26±0.58 versus 4.16±1.11, P =.0005) coronary reserves. In DM patients, the coronary reserve correlated strongly and inversely with the DNA mutation size ( r =−.77, P =.009). Conclusions The study demonstrated that global and regional coronary reserves are impaired, in relation to the DNA mutation size, in symptom-free DM patients with normal ventricular dimensions and function and normal large coronary vessels. We suggest that a gene-related blunted coronary reserve resulting from an impairment of vascular smooth muscle is an early component of DM cardiomyopathy.

Agyria-pachygyria or lissencephaly type I, a diffuse cortical malformation, provides infantile spasms (IS) which are refractory and persisting after the first decade, an age at which IS have disappeared in the other causes. In order to study the functional postnatal development of the lissencephalic cortex, we measured regional cerebral blood flow (rCBF) using SPECT (Single photon emission computed tomography) and 133Xe in 14 children with lissencephaly, aged from 4 months to 12 years (mean = 40 months) compared to normal children of the same age range and to children with cryptogenic IS aged from 3 months to 3 years (mean = 13 months). rCBF was calculated in frontal (FR) and parieto-temporo-occipital (PTO) cortex as well as the ratio FR/PTO. FR/PTO was higher in lissencephalic patients than in controls (P < 0.001) due to higher FR rCBF (P < 0.001), particularly in patients aged less than 3 years. FR/PTO was also higher in lissencephalic patients than in patients with cryptogenic IS (P < 0.001) also due to higher FR rCBF (P < 0.001). The values of FR/PTO and FR rCBF remained stable during the first years of life and did not exhibit any age- or topography-related changes as they do in controls or in patients with cryptogenic IS. These results suggest that the normal process of postnatal development in the brain is lacking in agyria-pachygyria. That could play a role in determining the persistance of epileptic spasms, the specific seizure type of this malformation.

Objective The authors investigated the metabolic maturation of the frontal cortex in pre-school autistic children. Method Regional cerebral blood flow (CBF) in five children with primary autism diagnosed according to the DSM-III-R criteria was studied longitudinally. Regional CBF in each of the autistic children was measured with single photon emission computed tomography twice during their development: at the age of 3-4 years and 3 years later. At each stage, the autistic children were compared to an age-matched comparison group of five nonautistic children with normal development. Results A transient frontal hypoperfusion was found in the autistic children at ages 3-4 years; this corresponded to the pattern of perfusion observed in much younger normal children. By the ages of 6-7, the autistic children's frontal perfusion had attained normal values. Conclusions Since CBF patterns in children are related to maturational changes in brain function, these results indicate a delayed frontal maturation in childhood autism. Such a delayed brain maturational process is consistent with the clinical data and cognitive performance of autistic children.

We have developed a method for the evaluation of the muscle glycogen content by natural abundance C13 NMR and we here evaluate its diagnostic value on a large number of muscle diseases (20 glycogenoses and 42 other myopathies) and 8 normal subjects. The results show high values of the glycogen/creatine ratio in muscle glycogenoses, with no overlap with other diseased or normal subjects. This evaluation of the muscle glycogen content, which is performed at rest and thus easily applicable, in particular for children, is thus very sensitive and specific for the diagnosis of muscle glycogenosis.

Стаття присвячена аналізу архітектур серверних платформ для корпоративних застосувань на мові програмування Java з використанням технологій Java EE, Spring, Akka та актуальності використання цих архітектур при зміні мови програмування. Декілька останніх років популярним є питання, яка мова замінить Java. Цінність використання Java для корпоративних застосувань складається не в самій мові, а у створених архітектурах та існуючому стеку технологій, які ефективно вирішують задачу розробки високонавантажених корпоративних систем. Розглянуто еволюцію серверних платформ для корпоративних застосувань від CORBA до Java EE/Spring/AKKA, виділені основні складові цих платформ. Проаналізовано як за допомогою Polyglot JVM можливо зберегти ці архітектури та технології в секторі корпоративних застосувань та при цьому додати інновації, пов’язані з появою нових мов програмування. One of the most frequent questions today is ‘what language will replace Java?’ What should we do with all the Java technologies for enterprise applications? These technologies are definitely valuable. Is it possible to replace a programming language and preserve the best practices at the same time? Yes - with Polyglot JVM. Introduction of Polyglot JVM has two goals: it clears the way to innovations and it allows to preserve Java enterprise technologies. Evolution of server platforms starting from CORBA to Java EE/Spring/Akka is analyzed and core platforms’ values are distinguished It is analyzed how to keep architectures of server platforms and introduce innovations driven by new programming languages. Статья посвящена анализу архитектур серверных платформ для корпоративных приложений на языке программирования Java с использованием технологий Java EE, Spring, Akka и актуальности использования этих архитектур при смене языка программирования. Последние несколько лет популярен вопрос о том, какой язык заменит язык Java. Ценность использования Java для корпоративных приложений состоит не в самом языке, а в выработанных архитектурах и существующем стеке технологий, которые эффективно решают задачу разработки высоконагруженных корпоративных систем. Рассмотрена эволюция серверных платформ для корпоративных приложений от CORBA до Java EE/Spring/AKKA, выделены основные составляющие этих платформа. Проанализировано как при помощи Polyglot JVM возможно сохранить архитектуры платформ в секторе корпоративных приложений и при этом привнести инновации, связанные с появлением новых языков программирования.

У статті на конкретному архівному матеріалі досліджено механізми фабрикування радянськими спец-службами так званої волинської філії «Польської організації військової» протягом 1935–1936 років. Установ-лено, що членами цієї «контрреволюційної організації» були названі особи, які реалізовували національну політику влади на місцях. Наголошено, що арешти «волинських пеовяків» здійснювалися паралельно з аналогічними викриттями в інших областях. З’ясовано методи ведення слідства та схарактеризовано прийняття репресивних рішень. Наголошено, що звинувачені були середнього віку, поляками за національністю й служ-бовцями за соціальним статусом. Доведено, що звинувачення були неконкретними й ґрунтувалися головним чином на показаннях морально зломлених в’язнів. Розкрито трагічні долі репресованих. Описано особливості процесу реабілітації постраждалих від свавілля каральних органів громадян. The article explores the mechanisms of forming the so-called Volyn section of the «Polish Military Organization» in 1935−1936 by Soviet Secret Services. As the study reveals, the abovementioned «counter-revolutionary organization» members appeared to be the following persons who were implementing the policy of the state in local areas. It is necessary to emphasize that the «Volyn peoviaks» arrests often coincided with similar cases in other fields. The investigation methods as well as the repressive verdicts are analyzed. The arrested usually appeared to be of middle age, of Polish descent and officials according to their social standing. As such, the uncertain accusations were based mainly on the testimonies of morally exhausted convicts. The further destiny of the arrested had a tragic ending. The article also reveals the details of the rehabilitation processes of the arrested ones.

La RGN a demande aux responsables des principaux etablissements et groupes industriels francais travaillant dans le domaine de l'energie nucleaire de synthetiser en un court developpement leur analyse sur l'evolution des activites nucleaires dans les prochaines annees. Cette analyse introduit la question essentielle a laquelle nous les avons invites a repondre : comment voyez-vous l'avenir du «nucleaire» de votre entreprise et quelles orientations strategiques avez-vous definies dans ce domaine pour la prochaine periode ?Nous remercions les «grands patrons» du secteur nucleaire francais d'avoir bien voulu repondre a ces interrogations prospectives.

Using repeated measurements of regional cerebral blood flow with positron emission tomography, we investigated the regional cortical activations induced in 10 normal subjects, by two different finger motor tasks, i.e., a repeated flexion-extension of all fingers and a repeated flexion-extension of the middle finger. The all-finger movement only activated the primary sensorimotor cortex (SM) and the supplementary motor area (SMA) contralateral to the movement. However, the activation of the SMA was clearly task related during this motor task, because it was only observed when the movement was triggered by an auditory cue but not when it was self-paced. The middle finger movement was performed during self-paced conditions. It induced a much more complex pattern of activation than the all-finger movement, characterized by a high degree of SM and SMA activation contralateral to the side of the movement, as well as a slight ipsilateral activation of these areas. We suggest that this pattern of cortical activation may reflect the process of individuating finger movement or the early stages of motor learning of this unusual and technically difficult movement. Our data also confirm that the SM activation is closely linked to the intrinsic parameters of the movement; while the SMA may be activated by different aspects of the movement realization and preparation.

Mostin vivostudies of striatal D2receptor (SD2R) density with positron emission tomography in schizophrenia have attempted to relate this variable to the diagnosis of the illness. In the present study, a relationship between SD2R and clinical dimensions of this psychosis was searched for in a highly selected group of young negative schizophrenics (8 drug-naïve and 2 drug-free). The SD2R density index measuredin vivousing76Br-bromolisuride and PET correlated negatively (r= 0.80,P< 0.01) with a psychomotor dimension of schizophrenia involving blunted affect and alogia. The mean SD2R index of the patients did not differ from that of age-matched control subjects. Therefore, this behavioural dimension accounts for the variance of the SD2R, suggesting that the striatal dopamine system modulates symptoms such as flattened affect and alogia.

The in vivo determination of the density of dihydropyridine (DHP) binding sites will allow the assessment of pathophysiological changes associated with heart disease. The calcium channel antogonist S 11568: ( + )(amino-7 dioxa-2,5 heptyl)-2(dichloro -2,3 phenyl) -4 methyl-6dihydro -1,4 pyridine has an in vitro profile of high potency and of high selectivity for the L-type Ca2+ channel. S 11568 was labelled by a reaction between 11C-diazomethane and the precursor 6-(7-amino-2,5-dioxa heptyl)-4-(2,3-dichloro phenyl)-5-(ethoxycarbonyl)-2 methyl-1,4 dihydro nicotinic acid. (+)-PN 200 110, a DHP with in vitro high affinity for the L-type Ca2+channel, was also radiolabeled. Positron emission tomographic (PET) studies of both 11C-DHP myocardial uptake were performed in Beagle dogs. 11C-(+)-PN 200 110 had a rapid wash-out from myocardium. In contrary, after a bolus injection, 11C-S 11568 myocardial concentration increased to reach a maximum in 1–2 minutes and then remained in a plateau with a slight downslope while the blood concentration fell rapidly. Myocardial uptake was 2 to 4 fold higher than lung uptake, leading to a good contrast on PET images. Pre-treatment with unlabeled S 11568 (2 μmol/kg or 6 μmol/kg over 15 minutes) reduced myocardial uptake by 60% and 80%, respectively. Specific binding was estimated during a displacement experiment: bolus of unlabeled S 11568 : 1 μmol/kg followed by a continuous infusion of 3 μmol/kg over 2 hours. It was found to represent 80% of the total binding. To assess influence of S11568 on coronary blood flow and therefore on the myocardial tracer delivery, coronary blood flow was measured using 15O-H2O and PET at baseline and following bolus injections of 0.4, 0.8, 2 μmol/kg of S 11568. Only the higher dose increased coronary blood flow. This is the in vivo demonstration of the binding characteristics to myocardial tissue of a DHP ligand. Such properties make S 11568 suitable for PET experiments. The studies of DHP binding sites will provided new insights concerning physiological situations as well as heart disease.

Most metabolic myopathies (like glycogenoses and mitochondrial myopathies) are related to inborn errors of muscle energy metabolism and often present clinically as exercise intolerance (inability to sustain normal exercise). We investigated whether the previously observed absence of normal exercise-induced variation in the T2 of muscle in McArdle's disease (a metabolic myopathy caused by muscle phosphorylase deficiency) was specific for this disease and whether the variations in T2 could be used for screening patients suspected of having metabolic myopathy.Exercise-induced variations in proton MR signal and in intracellular pH were studied in the forearm flexor muscles of nine healthy subjects and 49 patients with exercise intolerance due to muscle pain, suggesting a metabolic myopathy. The relative increase in T2, delta T2/T2, was measured from MR spin-echo images before and after exercise. Phosphocreatine (used as a control of the degree of exercise) and intracellular pH were measured from phosphorus-31 spectra before and during exercise. The progressive 4.5-min handgrip exercise reached maximal exertion capability at the end of exercise and decreased phosphocreatine to less than 50% of its rest value.Variations in T2 and end-exercise pH were correlated. The nine healthy subjects showed a delta T2/T2 ranging from +19% to +44% (but little T1 variation). Ten patients with McArdle's disease showed only slight delta T2/T2 (0-10%). There was no overlap with values for healthy subjects, but there was some with values for other patients. Of the 21 subjects with a delta T2/T2 less than 19%, 19 had a metabolic myopathy. The other two had a congenital neuromuscular disorder (one central core disease, one nemaline myopathy) with type I fiber predominance (type I muscle fibers are characterized by a high oxidative metabolism and a low lactic acid production).The altered increase in T2 was sensitive but not specific for McArdle's disease. However, as variations in T2 reflect variations in pH, they seem to be specific for myopathies in which there is little exercise-induced decrease in pH (some metabolic myopathies and congenital neuromuscular disorders with type I fiber predominance) among patients in whom exercise intolerance is the main symptom. Our results suggest that MR imaging might be useful as a screening test for these diseases.

Summary: Focal cortical disturbances are frequent sequelae in West syndrome (WS) even though it is a generalized epileptic syndrome. Functional neuroimaging was used to determine whether focal perfusion abnormalities exist at WS onset and change during evolution. We studied regional cerebral blood flow (rCBF) at different stages of WS. Mean CBF (mCBF) and rCBF were measured using SPECT (single photon emission computed tomography) and 133Xe in 13 WS patients: at onset (20 cases), just after steroids (17 cases), and after a mean follow-up of 2 years (26 cases). At WS onset, interictal mCBF was increased as the result of foci of hyper- and hypoperfusion, which were, respectively, mainly located in the frontal and posterior cortex. Just after steroid therapy, mCBF decreased without any focal predominance. During follow-up, hypoperfused foci remained unchanged whereas the frontal hyperperfused foci decreased after spasm control. Our results show that focal abnormalities are present at WS onset. Focal hypoactivity could reflect a cortical lesion responsible for WS and focal hyperactivity could play a role in the persistence of generalized epilepsy.

BACKGROUND Positron emission tomography (PET) with 11C-labeled CGP-12177 (CGP) has been shown to have the potential to noninvasively measure beta-adrenergic receptor concentration in dog heart. The present study was undertaken to evaluate the clinical value of this technique. METHODS AND RESULTS Eight normal subjects and 10 patients with heart failure related to an idiopathic cardiomyopathy were studied. Estimation of beta-receptor concentration was based on a graphic method applied on myocardial PET time-concentration curves obtained after an intravenous injection of 11C-CGP followed 30 minutes later by a coinjection of labeled and unlabeled CGP. The clinical tolerance of these injections was good. Left ventricular concentration of beta-receptors was decreased in patients compared with controls (3.12 +/- 0.51 versus 6.60 +/- 1.18 pmol/mL, respectively; p < 0.001). This 53% decrease agrees with previous in vitro data. In eight of the 10 patients, the beta-receptor concentration obtained from PET was compared with the beta-receptor density determined on left ventricular endomyocardial biopsy samples by in vitro binding technique using 3H-CGP-12177. Results obtained with both techniques were correlated (r = 0.79, p = 0.019). Moreover, decreased beta-receptor concentration correlated with the beta-contractile responsiveness to intracoronary dobutamine infusion (r = 0.83, p = 0.003), indicating a direct link between changes in the receptor number and its biological function. CONCLUSIONS PET appears to be a safe and reliable method of assessing in vivo changes in the number of left ventricular beta-adrenergic receptor sites of patients with idiopathic cardiomyopathy.

The thermal dependence of the translational diffusion coefficient and of the regional blood volume was investigated in vivo by using a special MR pulsed gradient technique with reduced sensitivity to bulk tissue motion. Measurements were done at 0.5 T, using a small gradient insert. The diffusion coefficient of muscle water was calibrated against thermocouple-measured temperature in vitro, both with the muscle fibers parallel and perpendicular to the diffusion gradient. The maximum muscle temperature variation obtained by percutaneous conduction was -8.8 +/- 1.6 degrees C under cooling and +3.7 +/- 1.6 degrees C under heating, from basal state. Simultaneously the fractional regional blood volume decreased by a factor of 3.5 under cooling and increased by a factor of 2.7 under heating. Due to the interdependence of microcirculation and tissue temperature, this technique may be used to follow heat production or deposition in living tissue (muscle exercise, electromagnetic irradiation, etc.).

We used MR imaging to locate and monitor in vivo the pathological events taking place 2 to 4 weeks after unilateral striatal injections of ibotenic acid (IA) in the Papio papio baboon. As early as 2 weeks after IA injections, excitotoxic lesions in the caudate and the putamen were directly visualized on T1-weighted images as small areas of low signal intensity. On T2-weighted images, the lesion sites were visualized as areas of highintensity signal, spreading over larger areas than the corresponding regions in T1-weighted images. These alterations of T2-values in the lesioned striatum persisted 4 weeks after surgery. However, as the striatal degeneration progressed from 2 to 4 weeks after lesion, the size of the areas of high signal intensity on T2-weighted images decreased, whereas the same regions appeared essentially unmodified on T1-weighted images. A marked enlargement of the ipsilateral lateral ventricle (a characteristic of excitotoxic striatal lesions) could be detected 4 weeks after surgery, on both axial T1- and T2-weighted images. Comparisons of MR images with postmortem anatomical data indicated that areas of increased T1 values corresponded to regions of severe neuronal depletion (a direct result of the excitotoxic lesion), whereas areas of increased T2 values corresponded to regions of increased content in astrocytes and ferritin and probably in the early period following lesion (2 weeks) to a superimposed edema.

The mathematical models can be very useful and even essential in some areas of the medicine. We describe the example of the use of the Positron Emission Tomography in order to quantify the concentration of receptors in the human heart. This quantification is only possible by using a mathematical model including the receptor concentration as parameter. Obviously in such a case, the justification of the identified model parameters has a great importance since an error can lead to erroneous diagnosis and to a maladjusted treatment. Since some years, it has been pointed out that the complete justification of complex models imposes to take into account and to develop new technical problems such as the estimation of the parameter uncertainties, the identifiability study and the experimental design. While studying the parameter estimation of the receptor-ligand model from Positron Emission Tomography data, each of the three possible conclusions to the identifiability problem (i.e. unidentifiability, multiple solutions or unique solution) were reached depending on the experimental protocol used. However, the possible multiplicity of the solutions has been found mainly by chance and we conclude that the usual approach allowing to study the model identifiability (both theoretical global identifiability and real local identifiability using the covariance matrix), is not sufficient to prove the uniqueness and thus the validity of the parameters.

In vivo glycogen metabolism was investigated at 2 Tesla by 13C NMR in the baboon liver. Two concentric surface coils were used for 13C observation and proton decoupling, respectively. Spectra were acquired in 2 to 10 minutes with a 60 ms repetition time. After 3 hours of glucose infusion in the 48 hr fasted animal, 3 g of 99%-enriched [1-13C]glucose were injected. The distribution of the label on C-1 and also C-2, C-5 and C-6 of glycogen indicated 65% and 35% contributions of the direct and indirect pathways to glycogen synthesis from glucose, respectively. The results show that hepatic metabolic pathways and rates can be followed in vivo in large animals by 13C NMR at 2 Tesla.

Using quantitative PET, the authors studied the binding of [11C]PK11195, a marker of activated microglia, in the thalamus of patients with chronic middle cerebral artery infarcts. All patients showed increased [11C]PK11195 binding in the ipsilateral thalamus, indicating the activation of microglia in degenerating projection areas remote from the primary lesion. A persistent increase in [11C]PK11195 binding suggests active, long-term thalamic microstructural changes after corticothalamic connection damage.

International audience; The superior temporal sulcus (STS) is specifically involved in processing the human voice. Profound acquired deafness by post-meningitis ossified cochlea and by bilateral vestibular schwannoma in neurofibromatosis type 2 patients are two indications for auditory brainstem implantation (ABI). In order to objectively measure the cortical voice processing of a group of ABI patients, we studied the activation of the human temporal voice areas (TVA) by PET H(2)(15)O, performed in a group of implanted deaf adults (n=7) with more than two years of auditory brainstem implant experience, with an intelligibility score average of 17%+/-17 [mean+/-SD]. Relative cerebral blood flow (rCBF) was measured in the three following conditions: during silence, while passive listening to human voice, and to non-voice stimuli. Compared to silence, the activations induced by voice and non-voice stimuli were bilaterally located in the superior temporal regions. However, compared to non-voice stimuli, the voice stimuli did not induce specific supplementary activation of the TVA along the STS. The comparison of ABI group with a normal-hearing controls group (n=7) showed that TVA activations were significantly enhanced among controls group. ABI allowed the transmission of sound stimuli to temporal brain regions but lacked transmitting the specific cues of the human voice to the TVA. Moreover, among groups, during silent condition, brain visual regions showed higher rCBF in ABI group, although temporal brain regions had higher rCBF in the controls group. ABI patients had consequently developed enhanced visual strategies to keep interacting with their environment.

The striatal D2 receptors of 19 untreated schizophrenics and 14 normal control subjects were investigated with PET and 76Br-bromolisuride. The ratio of radioactivity in the striatum to that in the cerebellum was taken as an index of the striatal D2 receptor density. There was no significant difference between the control and the schizophrenic groups, nor any difference between subgroups of patients defined by clinical type or course of illness, and no relationship between the striatum:cerebellum activity ratio and SANS or SAPS ratings of symptoms. Unlike in the controls, this ratio was not correlated with age in schizophrenics. This study suggests that there is no quantitative abnormality of striatal D2 dopamine receptors in schizophrenia.

We assessed the effect of nifedipine on myocardial perfusion and metabolism in 9 patients with systemic sclerosis, using positron emission tomography with a perfusion tracer (potassium-38) and a metabolic tracer (18F-fluorodeoxyglucose [18FDG]). Nifedipine, 20 mg 3 times daily for 1 week, induced a significant increase in 38K myocardial uptake, a significant decrease in 18FDG myocardial uptake, and a significant increase in the myocardial 38K: 18FDG ratio. These results indicate that the increase in myocardial perfusion is associated with modifications in myocardial energy metabolism, which probably result from a beneficial anti-ischemic effect of nifedipine in patients with systemic sclerosis.

SummaryThe cortical metabolic patterns of 12 schizophrenics experiencing hallucinations and/or pseudo-hallucinations were investigated using positron tomography and 18F-fluoro-deoxy-glucose. Andreasen's scales were scored and the patients (all “mixed“) were classified in a “positive” or a “negative” group and compared to a group of 6 normal controls. The data were analyzed across groups for absolute metabolic rates, metabolic indices (cortical region/whole studied cortex), and specific indices exploring the sensory non-association/posterior parietal association and the prefrontal association/posterior parietal association dimensions. Whole-cortex metabolic rate in the negative group was found to be lower than both the control (P=0.02) and the positive group (P = 0.002) while the positive group did not differ significantly from the controls. We found “hypofrontality” to be without difference between the positive and the negative group (controls: 7±0.7, positive: 5.9±0.2, negative: 4.9±0.15, mean±SEM in mg/min/100 g). However, the prefrontal association/posterior parietal association ratio was increased in the negative group (P=0.02). A major finding was an increase in the posterior non-association/posterior parietal association ratio in the whole schizophrenic group as compared to the controls (P = 0.004), this being more marked in the negative (P=0.01) than in the positive group. Arguments are given to support the hypothesis that this particular increase could be related to the hallucinatory activity of the patients.

International audience; UNLABELLED: Cochlear implants may improve the medical and social prognosis of profound deafness. Nevertheless, some patients have experienced poor results without any clear explanations. One correlate may be an alteration in cortical voice processing. To test this hypothesis, we studied the activation of human temporal voice areas (TVA) using a well-standardized PET paradigm adapted from previous functional MRI (fMRI) studies. METHODS: A PET H(2)(15)O activation study was performed on 3 groups of adult volunteers: normal-hearing control subjects (n = 6) and cochlear-implanted postlingually deaf patients with >2 y of cochlear implant experience, with intelligibility scores in the "Lafon monosyllabic task" >80% (GOOD group; n = 6) or

The in vivo quantification of myocardial muscarinic receptors has been obtained in six closed-chest dogs by using positron emission tomography. The dogs were injected with a trace amount of 11C-labeled methylquinuclidinyl benzilate (MQNB), a nonmetabolized antagonist of the muscarinic receptor. This was followed 30 minutes later by an injection of an excess of unlabeled MQNB (displacement experiment). Two additional injections of unlabeled MQNB with [11C]MQNB (coinjection experiment) and without [11C]MQNB (second displacement experiment) were administered after 70 and 120 minutes, respectively. This protocol allowed a separate evaluation of the quantity of available receptors (B'max) as well as the association and dissociation rate constants (k+1 and k-1) in each dog. The parameters were calculated by using a nonlinear mathematical model in regions of interest over the left ventricle and the interventricular septum. The average value of B'max was 42 +/- 11 pmol/ml tissue, the rate constants k+1, k-1, and Kd were 0.6 +/- 0.1 ml.pmol-1.min-1, 0.27 +/- 0.03 ml.pmol-1.min-1, and 0.49 +/- 0.14 pmol.ml-1, respectively, taking into account the MQNB reaction volume estimated to 0.15 ml/ml tissue. Although [11C]MQNB binding would appear irreversible, our findings indicate that the association of the antagonist is very rapid and that the dissociation is far from negligible. The dissociated ligand, however, has a high probability of rebinding to a free receptor site instead of escaping into the microcirculation. We deduce that the positron emission tomographic images obtained after injecting a trace amount of [11C]MQNB are more representative of blood flow than of receptor density or affinity. We also suggest a simplified protocol consisting of a tracer injection of [11C]MQNB and a second injection of an excess of cold MQNB, which is sufficient to measure B'max and Kd in humans.

The resting-state cerebral metabolic rates for glucose of 10 severely depressed patients (seven bipolar and three unipolar) were compared, before and after treatment with tricyclic antidepressants, to those of 10 control subjects of similar age by means of positron emission tomography and the fluorodeoxyglucose method. Significant left-right prefrontal asymmetry was present in the patients before but not after successful treatment, suggesting that medication can reduce this asymmetry. Also, significant hypofrontality and whole-cortex hypometabolism were found in the patients in the depressed state and persisted in the treated state, despite clinical improvement, suggesting that these abnormalities are not state dependent.

The authors compared 16 nondepressed obsessive-compulsive patients (OCS) with 8 normal controls (NC) of similar age for resting-state regional cerebral glucose metabolic rates (rCMRglu) using positron emission tomography with the fluorodeoxyglucose method. OCS were rated for clinical data, and a neuropsychological battery was administered to 14 patients on the day of the scan. Absolute rCMRglu for whole cortex, and normalized prefrontal lateral cortex metabolic rates, were both significantly lower in OCS than in NC. No significant difference between treated (n = 10) and drug-free (n = 6) OCS was found for those variables. OCS were significantly impaired in the neuropsychological tasks assessing memory and attention. The rCMRglu for prefrontal lateral cortex were negatively correlated to Stroop-test subscores. This "frontal-oriented" task assessed the ability of OCS to inhibit immediate but inappropriate responses. These results suggest, in OCS, a modification of the general activating systems of cortical function and a relationship between the lateral prefrontal rCMRglu decrease and a selective attention deficit.

TTV03, a novel high-spatial-resolution TOF-PET (time-of-flight positron emission tomography) system, is presented. The machine consists of four 89-cm-diameter rings made of 7-mm-wide, 18-mm-high, 45-mm-deep BaF/sub 2/ crystals (324 per ring) individually coupled to 11-mm-diameter phototubes. The transaxial resolution (full width at half maximum or FWHM) in the reconstructed image is 5.7 mm at center, 5.7 mm (tangential), and 6.5 mm (radial) at 10 cm. The axial resolution is 8.8 mm (direct plane) and 6.7 mm (crossplane) at center, and 10.3 mm (direct) and 11.2 mm (cross) at 10 cm from center. With a 150-keV threshold, the TOF resolution is 750 ps (FWHM), and, with a 4.18-ns coincidence window, the sensitivity (true evts/s per mu Ci/cm/sup 3/) is 9800 (direct plane) and 14300 (crossplane). At 1 mu Ci/cm/sup 3/, the ratio of random events to true events is .20 for the total and .03 per image element, and the scatter fraction is 22%. Dead time losses are 8.3% at 2.5 mu Ci/cm/sup 3/ (four rings), but the tomograph can handle activities over 50 mu Ci/cm/sup 3/ in small regions with negligible losses. These characteristics make TTV03 particularly suitable for dynamic brain and heart H/sub 2//sup 15/ bolus studies. >

Introduction This study reports on the biodistribution and radiation dosimetry of a cocaine analog, the (E)- N -(3-iodoprop-2-enyl)-2β-carbomethoxy-3β-(4′-tolyl)nortropane (PE2I), labeled with carbon 11 ([ 11 C]PE2I). [ 11 C]PE2I is used in positron emission tomography (PET) for examination of the dopamine neuronal transporter (DAT) . DAT radioligands are often used to evaluate the progression of Parkinson's disease or the efficiency of neuroprotective therapeutics, and, typically, these studies required several successive PET scans. Methods In three healthy male volunteers, whole-body scans were performed up to 2 h following intravenous injection of 321±6 MBq of [ 11 C]PE2I. For each subject, regions of interest were defined over all visible organs to generate time–activity curves and calculate the percentage of injected activity. Time–activity data were fitted to a monoexponential model, as an uptake phase followed by a mono-exponential washout, or bi-exponential model to obtain residence times. With the use of the MIRD method, several source organs were considered in estimating residence time and mean effective radiation absorbed doses. Results Blood pressure and ECG findings remained unchanged after radioligand injection. The primary route of clearance was renal. Ten minutes after injection, high activities were observed in the kidneys, urinary-bladder, stomach, liver, salivary glands and brain. The urine bladder wall, stomach and liver received the highest absorbed doses. The average effective dose of [ 11 C]PE2I was estimated to be 6.4±0.6 μSv/MBq. Conclusion The amount of [ 11 C]PE2I required for adequate DAT PET imaging results in an acceptable effective dose equivalent permitting two or three repeated cerebral PET studies, with the injection of 222 MBq for each study.