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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.
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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.
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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.
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Dendrobium/química , Fenantrenos/análisis , Extractos Vegetales/análisis , Australasia , Cromatografía Líquida de Alta Presión , Análisis Multivariante , Especificidad de la EspecieRESUMEN
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.
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Internacionalidad , Trastornos Mentales , Aislamiento Social/psicología , Adulto , Humanos , Japón , Trastornos Mentales/epidemiología , Trastornos Mentales/etiología , Trastornos Mentales/fisiopatología , Trastornos Mentales/terapia , Persona de Mediana Edad , Trastorno Obsesivo Compulsivo , Encuestas y Cuestionarios , SíndromeRESUMEN
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.
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Depresión/diagnóstico , Depresión/epidemiología , Adulto , Anciano , Australia , Bangladesh , Recolección de Datos , Depresión/clasificación , Trastorno Depresivo/diagnóstico , Manual Diagnóstico y Estadístico de los Trastornos Mentales , Estudios Epidemiológicos , Femenino , Humanos , India , Clasificación Internacional de Enfermedades , Irán , Japón/epidemiología , Corea (Geográfico) , Masculino , Persona de Mediana Edad , Personalidad , Trastornos de la Personalidad/diagnóstico , Psiquiatría , Suicidio , Encuestas y Cuestionarios , Taiwán , Tailandia , Estados Unidos , Adulto JovenRESUMEN
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.
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Certificación , Educación de Postgrado en Medicina , Psiquiatría/educación , Internado y Residencia , Japón , Encuestas y CuestionariosRESUMEN
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.
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Trastorno Obsesivo Compulsivo/fisiopatología , Diagnóstico por Imagen , Humanos , Tomografía de Emisión de Positrones , Tomografía Computarizada de Emisión de Fotón ÚnicoRESUMEN
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.
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Giro del Cíngulo/patología , Trastorno Obsesivo Compulsivo/patología , Adulto , Manual Diagnóstico y Estadístico de los Trastornos Mentales , Femenino , Lateralidad Funcional/fisiología , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Masculino , Escalas de Valoración PsiquiátricaRESUMEN
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.
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Benzazepinas/metabolismo , Benzofuranos/metabolismo , Receptores de Dopamina D1/metabolismo , Esquizofrenia/metabolismo , Adulto , Antipsicóticos/farmacología , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Corteza Cerebral/metabolismo , Cognición/efectos de los fármacos , Cuerpo Estriado/metabolismo , Femenino , Humanos , Ligandos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Tomografía de Emisión de Positrones , Receptores de Dopamina D1/efectos de los fármacosRESUMEN
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.
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Corteza Cerebral/metabolismo , Receptores de GABA-A/metabolismo , Esquizofrenia/metabolismo , Acetamidas/metabolismo , Adulto , Corteza Cerebral/diagnóstico por imagen , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neuroglía/metabolismo , Éteres Fenílicos/metabolismo , Tomografía de Emisión de Positrones , Esquizofrenia/diagnóstico por imagenRESUMEN
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.
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Corteza Cerebral/diagnóstico por imagen , Corteza Cerebral/metabolismo , Trastorno Obsesivo Compulsivo/diagnóstico por imagen , Trastorno Obsesivo Compulsivo/metabolismo , Proteínas de Transporte de Serotonina en la Membrana Plasmática/metabolismo , Adulto , Compuestos de Anilina , Encéfalo/patología , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Persona de Mediana Edad , Modelos Estadísticos , Trastorno Obsesivo Compulsivo/psicología , Tomografía de Emisión de Positrones , Escalas de Valoración Psiquiátrica , Radiofármacos , Sulfuros , Adulto JovenRESUMEN
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.
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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.
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Mapeo Encefálico , Dopaminérgicos/farmacocinética , Dopamina/biosíntesis , Tomografía de Emisión de Positrones , Esquizofrenia/diagnóstico por imagen , Esquizofrenia/metabolismo , Adulto , Radioisótopos de Carbono , Distribución de Chi-Cuadrado , Femenino , Humanos , Levodopa/farmacocinética , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Escalas de Valoración Psiquiátrica , Adulto JovenAsunto(s)
Trastornos Cerebrovasculares/etiología , Trastorno Obsesivo Compulsivo/fisiopatología , Corteza Prefrontal/irrigación sanguínea , Adulto , Mapeo Encefálico , Trastornos Cerebrovasculares/diagnóstico por imagen , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Persona de Mediana Edad , Trastorno Obsesivo Compulsivo/diagnóstico por imagen , Trastorno Obsesivo Compulsivo/psicología , Corteza Prefrontal/diagnóstico por imagen , Escalas de Valoración Psiquiátrica , Recurrencia , Tomografía Computarizada de Emisión de Fotón ÚnicoRESUMEN
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.
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Mapeo Encefálico , Imagen de Difusión por Resonancia Magnética/métodos , Trastorno Obsesivo Compulsivo/diagnóstico , Adulto , Anisotropía , Estudios de Casos y Controles , Difusión , Femenino , Lateralidad Funcional , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Masculino , Trastorno Obsesivo Compulsivo/fisiopatologíaAsunto(s)
Antidepresivos/administración & dosificación , Antidepresivos/metabolismo , Depresión/diagnóstico por imagen , Depresión/tratamiento farmacológico , Tomografía de Emisión de Positrones , Proteínas de Transporte de Serotonina en la Membrana Plasmática/metabolismo , Sitios de Unión , Unión Competitiva , Encéfalo/diagnóstico por imagen , Encéfalo/metabolismo , Radioisótopos de Carbono/metabolismo , Humanos , Unión Proteica , Radiofármacos/metabolismo , Proteínas de Transporte de Serotonina en la Membrana Plasmática/fisiología , Inhibidores Selectivos de la Recaptación de Serotonina/administración & dosificación , Inhibidores Selectivos de la Recaptación de Serotonina/metabolismoRESUMEN
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.
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Encéfalo/efectos de los fármacos , Butiratos/farmacocinética , Glicina/farmacología , Hidroxiquinolinas/farmacocinética , Tomografía de Emisión de Positrones/métodos , Pirrolidinonas/farmacocinética , Quinolonas/farmacocinética , Receptores de N-Metil-D-Aspartato/metabolismo , Adulto , Animales , Sitios de Unión/efectos de los fármacos , Encéfalo/metabolismo , Ciclosporinas/farmacología , Interacciones Farmacológicas , Inhibidores Enzimáticos/farmacología , Estudios de Factibilidad , Humanos , Masculino , Radiofármacos/farmacocinética , Ratas , Distribución TisularRESUMEN
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.
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Envejecimiento/fisiología , Imagen de Difusión por Resonancia Magnética , Lateralidad Funcional/fisiología , Tálamo/anatomía & histología , Tálamo/fisiología , Adulto , Anciano , Anisotropía , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
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.