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1.
Int J Surg Case Rep ; 121: 110056, 2024 Aug.
Article de Anglais | MEDLINE | ID: mdl-39029215

RÉSUMÉ

INTRODUCTION: Stenosis is a serious complication associated with stomas. The initial treatment for stoma stenosis is mainly the finger-bougie technique or balloon dilatation, and recurrence requires stomal reconstruction. However, the use of local triamcinolone injections for treating stoma stenosis has not been reported. Herein, we reported a case of repeated stoma stenosis in a high-risk patient in whom balloon dilatation combined with local triamcinolone injection effectively avoided stomal reconstruction. PRESENTATION OF CASE: A woman in her 70s was admitted to our hospital with the chief complaint of a positive fecal occult blood test and was diagnosed with Ra advanced rectal cancer. Owing to the presence of multiple comorbidities, a laparoscopic Hartmann procedure with D3 dissection was performed. The operative time was 165 min and the intraoperative blood loss was 5 mL. On postoperative day 2, the colostomy stump became discolored, and stoma necrosis was diagnosed, which was successfully treated conservatively, with no findings of stoma falling or peritonitis. Six months after surgery, late stoma stenosis causing colonic obstruction was diagnosed, and the finger-bougie technique and balloon dilatation were ineffective. To avoid reoperation under general anesthesia, balloon dilatation using a CRE™ PRO GI Wireguided (Boston Scientific) at 19 mm for 3 min combined with a 40 mg injection of local triamcinolone into the stoma orifice scar was successfully performed. DISCUSSION: No restenosis was observed after treatment. CONCLUSION: Balloon dilatation combined with local triamcinolone injections may be effective for recurrent stoma stenosis in patients with high-risk comorbidities after rectal cancer surgery.

2.
Sci Rep ; 13(1): 7517, 2023 May 09.
Article de Anglais | MEDLINE | ID: mdl-37161006

RÉSUMÉ

The complete automation of materials manufacturing with high productivity is a key problem in some materials processing. In floating zone (FZ) crystal growth, which is a manufacturing process for semiconductor wafers such as silicon, an operator adaptively controls the input parameters in accordance with the state of the crystal growth process. Since the operation dynamics of FZ crystal growth are complicated, automation is often difficult, and usually the process is manually controlled. Here we demonstrate automated control of FZ crystal growth by reinforcement learning using the dynamics predicted by Gaussian mixture modeling (GMM) from small numbers of trajectories. Our proposed method of constructing the control model is completely data-driven. Using an emulator program for FZ crystal growth, we show that the control model constructed by our proposed model can more accurately follow the ideal growth trajectory than demonstration trajectories created by human operation. Furthermore, we reveal that policy optimization near the demonstration trajectories realizes accurate control following the ideal trajectory.

3.
Chem Pharm Bull (Tokyo) ; 66(6): 642-650, 2018 Jun 01.
Article de Anglais | MEDLINE | ID: mdl-29618669

RÉSUMÉ

Genus Dendrobium (Orchidaceae) contains numerous species. Phylogenetic analyses based on morphological characteristics and DNA sequences indicated that this genus is divided into two major groups: Asian and Australasian clades. On the other hand, little is known about the phytochemical differences and similarities among the species in each clade. In this study, we selected 18 Dendrobium species (11 from the Asian clade and 7 from the Australasian clade) and constructed HPLC profiles, arrays composed of relative intensity of the chromatographic peaks. Next, orthogonal partial least square discriminant analysis (OPLS-DA) was applied to the profile matrix to classify Dendrobium species into the Asian and Australasian clades in order to identify the peaks that significantly contribute to the class separation. In the end, two phenanthrenes, 4,9-dimethoxyphenanthrene-2,5-diol 1 and 1,5-dimethoxyphenanthrene-2,7-diol 2, which contributed to the class separation, were isolated from the HPLC peaks. The existence of 2 was limited to the genetically related Australasian species.


Sujet(s)
Dendrobium/composition chimique , Phénanthrènes/analyse , Extraits de plantes/analyse , Australasie , Chromatographie en phase liquide à haute performance , Analyse multifactorielle , Spécificité d'espèce
4.
Soc Psychiatry Psychiatr Epidemiol ; 47(7): 1061-75, 2012 Jul.
Article de Anglais | MEDLINE | ID: mdl-21706238

RÉSUMÉ

PURPOSE: To explore whether the 'hikikomori' syndrome (social withdrawal) described in Japan exists in other countries, and if so, how patients with the syndrome are diagnosed and treated. METHODS: Two hikikomori case vignettes were sent to psychiatrists in Australia, Bangladesh, India, Iran, Japan, Korea, Taiwan, Thailand and the USA. Participants rated the syndrome's prevalence in their country, etiology, diagnosis, suicide risk, and treatment. RESULTS: Out of 247 responses to the questionnaire (123 from Japan and 124 from other countries), 239 were enrolled in the analysis. Respondents' felt the hikikomori syndrome is seen in all countries examined and especially in urban areas. Biopsychosocial, cultural, and environmental factors were all listed as probable causes of hikikomori, and differences among countries were not significant. Japanese psychiatrists suggested treatment in outpatient wards and some did not think that psychiatric treatment is necessary. Psychiatrists in other countries opted for more active treatment such as hospitalization. CONCLUSIONS: Patients with the hikikomori syndrome are perceived as occurring across a variety of cultures by psychiatrists in multiple countries. Our results provide a rational basis for study of the existence and epidemiology of hikikomori in clinical or community populations in international settings.


Sujet(s)
Internationalité , Troubles mentaux , Isolement social/psychologie , Adulte , Humains , Japon , Troubles mentaux/épidémiologie , Troubles mentaux/étiologie , Troubles mentaux/physiopathologie , Troubles mentaux/thérapie , Adulte d'âge moyen , Trouble obsessionnel compulsif , Enquêtes et questionnaires , Syndrome
5.
J Affect Disord ; 135(1-3): 66-76, 2011 Dec.
Article de Anglais | MEDLINE | ID: mdl-21782250

RÉSUMÉ

AIM: Japanese psychiatrists have increasingly reported patients with depression that does not seem to fit the criteria of the ICD-10 and the DSM-IV, and which has recently been called modern type depression (MTD). We explored whether MTD is frequently seen in Japan and also in other countries, and if so, how patients with MTD are diagnosed and treated. METHODS: The questionnaires, with two case vignettes (traditional type depression (TTD) and MTD), were sent to psychiatrists in Australia, Bangladesh, India, Iran, Japan, Korea, Taiwan, Thailand and the USA. Participants rated their opinions about each case's prevalence in their country, etiology, diagnosis, suicide risk, and treatment using Likert scales. RESULTS: Out of 247 responses (123 from Japan and 124 from other countries), two hundred thirty-nine valid responses were received. MTD was recognized in all participating countries, and especially in urban areas. Generally, the factor of personality was regarded as the most probable cause of MTD. Whereas about 90% of Japanese psychiatrists applied the ICD/DSM criteria to TTD, only about 60% applied the criteria to MTD. CONCLUSION: Our results indicate that Japan's MTD seems to be occurring in many other countries, and that the present ICD/DSM criteria may not be sufficient to diagnose MTD. Therefore, it could be an important candidate for a new international diagnostic criterion as a subtype of depression. A clear diagnostic framework and consensus on the interventions to treat MTD would be valuable. Further clinical, psychopathological and international epidemiological studies are needed to confirm our preliminary findings of MTD.


Sujet(s)
Dépression/diagnostic , Dépression/épidémiologie , Adulte , Sujet âgé , Australie , Bangladesh , Collecte de données , Dépression/classification , Trouble dépressif/diagnostic , Diagnostic and stastistical manual of mental disorders (USA) , Études épidémiologiques , Femelle , Humains , Inde , Classification internationale des maladies , Iran , Japon/épidémiologie , Corée , Mâle , Adulte d'âge moyen , Personnalité , Troubles de la personnalité/diagnostic , Psychiatrie , Suicide , Enquêtes et questionnaires , Taïwan , Thaïlande , États-Unis , Jeune adulte
6.
Seishin Shinkeigaku Zasshi ; 113(3): 271-6, 2011.
Article de Japonais | MEDLINE | ID: mdl-21591403

RÉSUMÉ

The psychiatric specialist certification system of the Japanese Society of Psychiatry and Neurology was established in 2005, with a transitional period that ran until 2008. A three-year postgraduate training scheme was started in connection with the new psychiatric specialist certification system, and the first formal examination under the new system was held in 2010. A resident desiring certification as a psychiatric specialist must purchase a psychiatric specialist certification handbook and present it when taking the examination. There are many differences between the new examination and the transitional period examination, in terms of both the handbook and the number of case reports to be submitted. Results of a survey conducted on 360 psychiatrists belonging to either university or national hospitals, all of whom had undergone psychiatric training within the past eight years, revealed that there was currently a lack of knowledge, and low rate of utilization, of the handbook. The primary author was in the first cohort of those who began postgraduate psychiatric training in a university hospital and subsequently took the first examination administered after the transition period. The author has maintained that, based on personal experience, a number of issues need improvement, such as the large number of grading items to be signed off on by supervising psychiatrists, and complications involving the outline of cases to be experienced. Additionally, it was thought to be difficult for supervisors who had obtained their specialist certification via the transitional period examination to have an adequate understanding of the outline of the new examination. Therefore, it is important that residents themselves take a more assertive attitude to becoming specialists. In the future, in order to establish a sound specialist certification system, the results of this survey of physicians who took the new examination should be taken into account.


Sujet(s)
Attestation , Enseignement spécialisé en médecine , Psychiatrie/enseignement et éducation , Internat et résidence , Japon , Enquêtes et questionnaires
7.
Seishin Shinkeigaku Zasshi ; 113(1): 45-53, 2011.
Article de Japonais | MEDLINE | ID: mdl-21404631

RÉSUMÉ

Hypotheses of pathophysiology in obsessive-compulsive disorder (OCD) have developed in parallel with advances in neuroimaging. Based on findings from early PET and SPECT studies evaluating cerebral blood flow and glucose metabolism, one theory proposed involvement of the orbitofrontal-striatum-thalamus loop (the "OCD loop"), which is relevant to the enforced learning and maintenance of OC symptoms. This OCD loop hypothesis has been revised in accordance with advances in neuroimaging techniques and the accumulation of findings. PET and SPECT molecular neuroimaging studies have provided the biological evidence to support the serotonin and dopamine hypotheses that were based on psychopharmacological findings. A symptom dimension hypothesis, based on symptomatology, has also been proposed. Neuroimaging has revealed the distinct neural basis of each symptom dimension. Neuroimaging has contributed to understanding the pathophysiology of OCD, and is expected to contribute to the development of treatment.


Sujet(s)
Trouble obsessionnel compulsif/physiopathologie , Imagerie diagnostique , Humains , Tomographie par émission de positons , Tomographie par émission monophotonique
8.
Psychiatry Clin Neurosci ; 64(5): 541-7, 2010 Oct.
Article de Anglais | MEDLINE | ID: mdl-20923432

RÉSUMÉ

AIMS: Previous morphometric studies using magnetic resonance imaging (MRI) have revealed structural brain abnormalities in obsessive-compulsive disorder (OCD). The aim of the present study was to investigate the alterations in brain structure of patients with OCD using a voxel-based morphometry (VBM) method. METHODS: Sixteen patients with OCD free of comorbid major depression, and 32 sex- and age-matched healthy subjects underwent MRI using a 1.5-T MR scanner. OCD severity was assessed with the Yale-Brown Obsessive-Compulsive Scale (mean ± SD: 22 ± 7.6; range: 7-32). MR images were spatially normalized and segmented using the VBM5 package (http://dbm.neuro.uni-jena.de/vbm/). Statistical analysis was performed using statistical parametric mapping software. RESULTS: Significant reductions in regional gray matter volume were detected in the left caudal anterior cingulate cortex and right dorsal posterior cingulate cortex in the patients with OCD as compared to healthy controls (uncorrected, P < 0.001). No significant differences in white matter volumes were observed in any brain regions of the patients. No significant correlation between Yale-Brown Obsessive-Compulsive Scale score and regional gray matter or white matter volume was observed. CONCLUSIONS: Regional gray matter alteration in the dorsal cingulate cortex, which is suggested to play a role in non-emotional cognitive processes, may be related to the pathophysiology in OCD.


Sujet(s)
Gyrus du cingulum/anatomopathologie , Trouble obsessionnel compulsif/anatomopathologie , Adulte , Diagnostic and stastistical manual of mental disorders (USA) , Femelle , Latéralité fonctionnelle/physiologie , Humains , Traitement d'image par ordinateur , Imagerie par résonance magnétique , Mâle , Échelles d'évaluation en psychiatrie
9.
Life Sci ; 86(21-22): 814-8, 2010 May 22.
Article de Anglais | MEDLINE | ID: mdl-20361984

RÉSUMÉ

AIMS: Abnormality of cognitive function in schizophrenia has been suggested to be related to dopamine D1 receptor. However, the results of previous positron emission tomography (PET) studies of dopamine D1 receptor in schizophrenia were not consistent. MAIN METHODS: In this study, six patients with schizophrenia in severe residual phase with chronic antipsychotic treatment and twelve healthy age-matched controls participated. Two different radioligands, [11C]NNC112 and [11C]SCH23390, for dopamine D1 receptor were used on the same subjects. Binding of the ligands was measured by PET, and statistical analysis was performed using one-way analysis of covariate (ANCOVA) with age as covariate. KEY FINDINGS: Good correlations between binding potential values (BP(ND)) and age were observed in all regions of interest (ROIs) with both ligands. ANCOVA with age as covariate of BP(ND) values of all ROIs revealed that the patient group showed significantly lower BP(ND) value compared with the control group in both ligands. SIGNIFICANCE: In patients with chronic schizophrenia in severe residual phase with chronic antipsychotic treatment, the binding potential values of both ligands were significantly lower in the striatum and cortical regions than those of healthy controls.


Sujet(s)
Benzazépines/métabolisme , Benzofuranes/métabolisme , Récepteur dopamine D1/métabolisme , Schizophrénie/métabolisme , Adulte , Neuroleptiques/pharmacologie , Encéphale/effets des médicaments et des substances chimiques , Encéphale/métabolisme , Cortex cérébral/métabolisme , Cognition/effets des médicaments et des substances chimiques , Corps strié/métabolisme , Femelle , Humains , Ligands , Imagerie par résonance magnétique , Mâle , Adulte d'âge moyen , Tomographie par émission de positons , Récepteur dopamine D1/effets des médicaments et des substances chimiques
10.
Int J Neuropsychopharmacol ; 13(7): 943-50, 2010 Aug.
Article de Anglais | MEDLINE | ID: mdl-20350336

RÉSUMÉ

Inflammatory/immunological process and glial contribution are suggested in the pathophysiology of schizophrenia. We investigated peripheral benzodiazepine receptors in brains of patients with chronic schizophrenia, which were reported to be located on mitochondria of glial cells, using [11C]DAA1106 with positron emission tomography. Fourteen patients and 14 age- and sex-matched normal controls participated in this study. PET data were analysed by two-tissue compartment model with metabolite-corrected plasma input. Clinical symptoms were assessed using the Positive and Negative Syndrome Scale. There was no significant difference between [11C]DAA1106 binding of the cortical regions of normal controls and patients with schizophrenia, whereas the patients showed a positive correlation between cortical [11C]DAA1106 binding and positive symptom scores. There was also a positive correlation between [11C]DAA1106 binding and duration of illness. Although the correlations need to be interpreted very cautiously, involvement of glial reaction process in the pathophysiology of positive symptoms or progressive change of schizophrenia might be suggested.


Sujet(s)
Cortex cérébral/métabolisme , Récepteurs GABA-A/métabolisme , Schizophrénie/métabolisme , Acétamides/métabolisme , Adulte , Cortex cérébral/imagerie diagnostique , Femelle , Humains , Mâle , Adulte d'âge moyen , Névroglie/métabolisme , Éthers phényliques/métabolisme , Tomographie par émission de positons , Schizophrénie/imagerie diagnostique
11.
Neuroimage ; 49(1): 121-6, 2010 Jan 01.
Article de Anglais | MEDLINE | ID: mdl-19660554

RÉSUMÉ

The serotonin transporter (5-HTT) and other markers of the serotonergic system have been of interest in the pathophysiology of obsessive-compulsive disorder (OCD). Previous studies using single photon emission computed tomography (SPECT) with [(123)I]beta-CIT or positron emission tomography (PET) with [(11)C]McN5652 have not shown consistent findings about 5-HTT in OCD patients. The aim of the present study was to investigate 5-HTT binding using [(11)C]DASB, which has higher selectivity or specific binding-to-nonspecific binding ratios for 5-HTT compared to the aforementioned radioligands. Four drug-naive and 6 drug-free patients with OCD who were free of comorbid depression and 18 gender and age-matched healthy subjects underwent PET scans with [(11)C]DASB. The severity of OCD was assessed by Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) (mean+/-SD: 22+/-7.6, range: 7-32). The binding potential (BP(ND)) of [(11)C]DASB was calculated using a two-parameter multilinear reference tissue model (MRTM2). The parametric images of BP(ND) were analyzed using a statistical parametric mapping system. Significant reductions of BP(ND) were observed in the right posterior and left anterior insular cortices in patients with OCD compared to controls. Region-of-interest analysis has also confirmed significant reduction of BP(ND) in the insular cortex. Although significantly reduced BP(ND) in the orbitofrontal cortex was also observed in patients with OCD compared to controls, this finding should be considered with caution because of the very low 5-HTT binding in the region. On the other hand, no significant correlation was observed between the Y-BOCS score and BP(ND). The change in [(11)C]DASB binding in the insular cortex suggests that dysfunction of the serotonergic system in the limbic area might be involved in the pathophysiology of OCD.


Sujet(s)
Cortex cérébral/imagerie diagnostique , Cortex cérébral/métabolisme , Trouble obsessionnel compulsif/imagerie diagnostique , Trouble obsessionnel compulsif/métabolisme , Transporteurs de la sérotonine/métabolisme , Adulte , Dérivés de l'aniline , Encéphale/anatomopathologie , Femelle , Humains , Traitement d'image par ordinateur , Mâle , Adulte d'âge moyen , Modèles statistiques , Trouble obsessionnel compulsif/psychologie , Tomographie par émission de positons , Échelles d'évaluation en psychiatrie , Radiopharmaceutiques , Sulfures , Jeune adulte
13.
Asian J Psychiatr ; 2(4): 154-5, 2009 Dec.
Article de Anglais | MEDLINE | ID: mdl-23051097

RÉSUMÉ

Japan Young Psychiatrists Organization was founded in 2002. The Course for Academic Development of Psychiatrists (CADP) held in 2001 was the momentum to establish JYPO. CADP is the course designed by Professor N. Sartorius for the purpose of developing professional and leadership skills of young psychiatrists. From then, JYPO have continued to hold CADP annually. Now we JYPO welcome the participants of CADP from overseas. We aim to introduce the detailed contents of CADP to the Asian colleague and encourage them to participate in CADP.

14.
Schizophr Res ; 108(1-3): 78-84, 2009 Mar.
Article de Anglais | MEDLINE | ID: mdl-19056247

RÉSUMÉ

The dopamine hypothesis has been the most widely known theory concerning schizophrenia. However, the exact mechanism including presynaptic dopaminergic activity and its relationship with symptom severity still remains to be revealed. We measured presynaptic dopamine synthesis using positron emission tomography (PET) with L-[beta-(11)C]DOPA in 18 patients with schizophrenia (14 drug-naive and 4 drug-free patients) and 20 control participants. Dopamine synthesis rates, expressed as k(i) values, were obtained using a graphical method, and the occipital cortex was used as reference region. Regions of interest were placed on the prefrontal cortex, temporal cortex, anterior cingulate, parahippocampus, thalamus, caudate nucleus, and putamen. Psychopathology was assessed with the Positive and Negative Symptom Scale (PANSS). We found significantly higher k(i) values in patients than in controls in the left caudate nucleus, but not in the other regions. The k(i) values in the thalamus exhibited a significant positive correlation with the PANSS total scores. Furthermore, a significant positive correlation was observed between the PANSS positive subscale scores and k(i) values in the right temporal cortex. Patients with schizophrenia showed higher dopamine synthesis in the left caudate nucleus, and dopaminergic transmission in the thalamus and right temporal cortex might be implicated in the expression of symptoms in schizophrenia.


Sujet(s)
Cartographie cérébrale , Agents dopaminergiques/pharmacocinétique , Dopamine/biosynthèse , Tomographie par émission de positons , Schizophrénie/imagerie diagnostique , Schizophrénie/métabolisme , Adulte , Radio-isotopes du carbone , Loi du khi-deux , Femelle , Humains , Lévodopa/pharmacocinétique , Imagerie par résonance magnétique/méthodes , Mâle , Adulte d'âge moyen , Échelles d'évaluation en psychiatrie , Jeune adulte
16.
Prog Neuropsychopharmacol Biol Psychiatry ; 32(5): 1221-6, 2008 Jul 01.
Article de Anglais | MEDLINE | ID: mdl-18442878

RÉSUMÉ

BACKGROUND: Abnormalities of fractional anisotropy (FA) have been reported in previous diffusion tensor imaging (DTI) studies in patients with obsessive-compulsive disorder (OCD). However, there are some inconsistencies in the results and the apparent diffusion coefficient (ADC) has not been investigated. The goal of this study was to investigate white matter abnormalities and water diffusivity, as reflected by FA and ADC, using DTI in patients with OCD. METHODS: Fifteen patients with OCD and 15 healthy volunteers underwent DTI. Voxelwise analysis was used to compare FA in white matter and ADC in gray matter/white matter of the two groups. RESULTS: Compared with healthy volunteers, the patients had higher FA in the bilateral semioval center extending to the subinsular white matter; and a higher ADC in the left medial frontal cortex. There were no areas with a significantly lower FA or ADC in patients compared with healthy volunteers. CONCLUSIONS: A significantly higher FA was found in regions associated with the emotion of disgust and a trend for a higher ADC was found in a region associated with the regulation of emotions. These findings suggest that neurocircuits involved in disgust processing may play an important role in the pathophysiology of OCD.


Sujet(s)
Cartographie cérébrale , Imagerie par résonance magnétique de diffusion/méthodes , Trouble obsessionnel compulsif/diagnostic , Adulte , Anisotropie , Études cas-témoins , Diffusion , Femelle , Latéralité fonctionnelle , Humains , Traitement d'image par ordinateur/méthodes , Mâle , Trouble obsessionnel compulsif/physiopathologie
18.
Synapse ; 61(10): 795-800, 2007 Oct.
Article de Anglais | MEDLINE | ID: mdl-17598152

RÉSUMÉ

N-methyl-D-aspartate (NMDA) receptors are of major interest in brain functions and neuropsychiatric disorders. However, at present there are few suitable radioligands for in vivo imaging of NMDA receptors. 7-choloro-4-hydroxy-3-[3-(4-methoxybenzyl) phenyl]-2(1H)-quinolone (L-703,717) is one of the potent ligands for the glycine-binding site of NMDA receptors. 4-Acetoxy derivative of L-703,717 (AcL703) is a candidate, as a positron emission tomography (PET) ligand for NMDA receptors, because of its better permeability at the blood-brain barrier compared with L-703,717. After intravenous injection of 624-851 MBq of [11C]AcL703, dynamic PET scan was performed on six healthy males for 90 min. Regions-of-interest were located on the cerebral cortices, cerebellar cortex, and cerebral white matter. The binding potential (BP) was calculated from the ratio of the area under the curve (AUC) of radioactivities from 40 to 90 min in the target region to that in white matter. Regional radioactivities reached close to equilibrium in all regions after about 40 min postinjection. Regional brain uptake of [11C]AcL703 at 40 min after injection was 0.00028-0.00065% of the injected dose/milliliter. Radioactivity concentration of [11C]AcL703 was highest in the cerebellar cortex and lowest in white matter. AUC in the cerebellar cortex was higher than those of cerebral cortices, thalamus, striatum, and white matter. BP in the cerebellar cortex was twofold higher than in the cerebral cortices (cerebellar cortex: BP=2.20+/-0.72; cerebral cortices: BP=1.05+/-0.45). Despite the low brain uptake of [11C]AcL703, regional distributions were in good agreement with our previous studies of rodents. This indicates the possibility of in vivo evaluation of NMDA receptors using PET with [11C]AcL703 in living human brain.


Sujet(s)
Encéphale/effets des médicaments et des substances chimiques , Butyrates/pharmacocinétique , Glycine/pharmacologie , Hydroxyquinoléines/pharmacocinétique , Tomographie par émission de positons/méthodes , Pyrrolidones/pharmacocinétique , Quinolinone/pharmacocinétique , Récepteurs du N-méthyl-D-aspartate/métabolisme , Adulte , Animaux , Sites de fixation/effets des médicaments et des substances chimiques , Encéphale/métabolisme , Cyclosporines/pharmacologie , Interactions médicamenteuses , Antienzymes/pharmacologie , Études de faisabilité , Humains , Mâle , Radiopharmaceutiques/pharmacocinétique , Rats , Distribution tissulaire
19.
Neuroreport ; 18(10): 1071-5, 2007 Jul 02.
Article de Anglais | MEDLINE | ID: mdl-17558299

RÉSUMÉ

Thalamic nuclei are comprised of fibers connecting associated cortical regions, and abnormalities of the thalamus are correlated with abnormalities in cognition and behavior. Some previous studies showed the laterality of the whole thalamus and the regional differences among thalamic nuclei. This led us to assess regional characteristics in five major subregions of both sides of the thalamus using diffusion-tensor imaging. Statistically significant lateralities and regional differences were found among the thalamic subregions. Age has a significant correlation with diffusion-tensor imaging metrics where their projection areas are thought to be vulnerable to normal aging. Our results confirmed that the thalamic subregions behave independently, and their respective microstructures warrant further investigations.


Sujet(s)
Vieillissement/physiologie , Imagerie par résonance magnétique de diffusion , Latéralité fonctionnelle/physiologie , Thalamus/anatomie et histologie , Thalamus/physiologie , Adulte , Sujet âgé , Anisotropie , Femelle , Humains , Mâle , Adulte d'âge moyen
20.
Cortex ; 43(3): 389-96, 2007 Apr.
Article de Anglais | MEDLINE | ID: mdl-17533762

RÉSUMÉ

When humans manipulate a control device under operational rules, with the goal of indirectly controlling a remote tool to achieve a desired outcome, they may rely on the power of internal representation to organize individual moves of the controller and tool into a set of sequences by mapping the motor space among hand, controller and tool. We recently used functional brain imaging (PET) to investigate activations in monkey brain associated with joystick-controlled remote operation of a shovel to obtain food. Activated areas included the prefrontal cortex, posterior parietal cortex and cerebellum, regardless of the rules relating movements of the joystick to those of the shovel (Obayashi et al., 2004). If those areas are engaged in the mental manipulation of internal representation, then we should expect brain activity in the same regions during any similar remote operation, even with different controllers and/or operational rules. To address the above hypothesis in the current study, we used PET to measure regional cerebral blood flow (rCBF) of two monkeys during a task in which they were required to control a shovel remotely (to fetch a food pellet) by manipulating dual dials. Compared to unplanned movement of the dials, the active dual-dial operation was associated with robust activation of the prefrontal cortex, higher-order motor cortex, posterior parietal cortex and cerebellum, quite similar to that observed during remote operation with a joystick. The present study suggests that monkeys might be able to organize abstract sequential operations according to learned rules, and perhaps indeed to have insight into the nature of the causal relationships, implying the existence of a relatively sophisticated system of internal representation in the absence of language. The fact that the present results are consistent with our previous PET studies strengthens the view that the underlying mechanism for implicit manipulation of internal representations may involve a cerebro-cerebellar neural circuit including the frontal and parietal cortex.


Sujet(s)
Cartographie cérébrale , Macaca/physiologie , Mouvement/physiologie , Résolution de problème/physiologie , Comportement d'utilisation d'outil/physiologie , Animaux , Encéphale , Cervelet/physiologie , Lobe frontal/physiologie , Imagination/physiologie , Intention , Mâle , Lobe pariétal/physiologie , Tomographie par émission de positons
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