Biomedical subjects

Hiroaki Kumano

Publications and source records attributed to Hiroaki Kumano.

At least 19 recordsLinked to original sources

PubMed2006

Fluvoxamine, a selective serotonin reuptake inhibitor, and 5-HT2C receptor inactivation induce appetite-suppressing effects in mice via 5-HT1B receptors.

Serotonin (5-hydroxytryptamine; 5-HT) 2C receptors and the downstream melanocortin pathway are suggested to mediate the appetite-suppressing effects of 5-HT drugs such as m-chlorophenylpiperazine (mCPP) and fenfluramine. Here, we report that fluvoxamine (3-30 mg/kg), a selective serotonin reuptake inhibitor (SSRI), in the presence of SB 242084 (1-2 mg/kg), a selective 5-HT2C receptor antagonist, exerts appetite-suppressing effects while fluvoxamine or SB 242084 alone has no effect. The appetite-suppressing effects were attenuated in the presence of SB 224289 (5 mg/kg), a selective 5-HT1B receptor antagonist. Moreover, CP 94253 (5-10 mg/kg), a selective 5-HT1B receptor agonist, exerted appetite-suppressing effects and significantly increased hypothalamic pro-opiomelanocortin (POMC) and cocaine- and amphetamine-regulated transcript (CART) gene expression and decreased hypothalamic orexin gene expression. These results suggest that fluvoxamine and inactivation of 5-HT2C receptors exert feeding suppression through activation of 5-HT1B receptors, and that 5-HT1B receptors up-regulate hypothalamic POMC and CART gene expression and down-regulate hypothalamic orexin gene expression in mice.

Analysis of Variance↗

PubMed2006

Changes in cerebral glucose utilization in patients with panic disorder treated with cognitive-behavioral therapy.

Several neuroanatomical hypotheses of panic disorder have been proposed focusing on the significant role of the amygdala and PAG-related "panic neurocircuitry." Although cognitive-behavioral therapy is effective in patients with panic disorder, its therapeutic mechanism of action in the brain remains unclear. The present study was performed to investigate regional brain glucose metabolic changes associated with successful completion of cognitive-behavioral therapy in panic disorder patients. The regional glucose utilization in patients with panic disorder was compared before and after cognitive-behavioral therapy using positron emission tomography with (18)F-fluorodeoxyglucose. In 11 of 12 patients who showed improvement after cognitive-behavioral therapy, decreased glucose utilization was detected in the right hippocampus, left anterior cingulate, left cerebellum, and pons, whereas increased glucose utilization was seen in the bilateral medial prefrontal cortices. Significant correlations were found between the percent change relative to the pretreatment value of glucose utilization in the left medial prefrontal cortex and those of anxiety and agoraphobia-related subscale of the Panic Disorder Severity Scale, and between that of the midbrain and that of the number of panic attacks during the 4 weeks before each scan in all 12 patients. The completion of successful cognitive-behavioral therapy involved not only reduction of the baseline hyperactivity in several brain areas but also adaptive metabolic changes of the bilateral medial prefrontal cortices in panic disorder patients.

Adult↗

PubMed2006

Does the Aging Males' Symptoms scale assess major depressive disorder?: A pilot study.

OBJECTIVES: The objectives of the study were to find the prevalence of major depressive disorder (MDD) in male climacteric outpatients in Japan, and to determine whether symptoms on the Aging Males' Symptoms (AMS) scale scores differed between patients with and without MDD, with the aim of increasing the specificity of future symptoms scales for partial androgen deficiency of the aging male (PADAM). METHODS: Eighty-three patients aged 40-70 who visited the male-climacteric services as outpatients were assessed using three items: a self-administered questionnaire corresponding to diagnosis for MDD, the Beck Depression Inventory, and the AMS scale. RESULTS: Almost half the patients had MDD. The total AMS score, the scores on the AMS psychological, somatic and sexual subscales, and the scores for all except three questionnaire symptoms were higher in patients with MDD. There were strong correlations between the AMS scale and the Beck Depression Inventory. CONCLUSIONS: There is a higher prevalence of MDD in male-climacteric outpatients and scores on most items of the AMS scale were higher for patients with MDD. We suggest that only those symptoms whose scores did not differ between patients with and without MDD are used to assess symptoms of PADAM in the presence of MDD, or that the current AMS is used only after diagnosis of MDD and elimination of these patients. Then the relevance of each item of the AMS to testosterone levels should be simultaneously examined in the future study, which will determine the items highly specific to PADAM symptoms.

Adult↗

PubMed2006

Bulimia nervosa and abnormal cardiac repolarization.

OBJECTIVE: Eating disorders (ED) are thought to be risk factors for sudden death, and arrhythmias are one of the major causes of sudden death in ED patients. Late potentials (LPs) are a predictor of arrhythmias and can be measured using signal-averaged electrocardiography (SAECG). We examined arryhthmogenicity by LPs in ED patients. METHODS: We performed SAECG on 48 female ED patients [21 with anorexia nervosa (AN) and 27 with bulimia nervosa (BN)] and on 20 healthy women. An LP was judged positive if two or more of the following criteria were fulfilled: QRS duration >120 ms, root-mean-square voltage <20 microV, and a high-frequency, low-amplitude duration >38 ms. We compared the occurrence of LPs among subgroups. RESULTS: Compared with the controls, BN patients with a history of AN had significantly more SAECG abnormalities. CONCLUSIONS: BN patients with a history of AN may be prone to ventricular arrhythmias.

Adult↗

PubMed2006

Changes in heart rate with refeeding in anorexia nervosa: a pilot study.

OBJECTIVE: To find differences in heart rate before and after refeeding and to identify which parameters of autonomic activity and endocrine function are associated with these differences. METHODS: Before and after the start of refeeding, body weight, RR interval (RRI), heart rate variability, endocrine function, and energy expenditure were measured in nine female anorexia nervosa patients. RESULTS: After short-term refeeding, mean daytime heart rate rose from 54.9 to 69.4 bpm (P<.05). The changes in sympathetic activity were correlated negatively with the changes in RRI (r=-.933, P<.001). Urine C-peptide, IGF-1, and fT3 increased significantly, and norepinephrine tended to increase. CONCLUSION: We demonstrated that autonomic nervous activity was relevant to changes in heart rate during refeeding, and it is speculated that the increases in insulin secretion, thyroid function, and IGF-1 were responsible for the mechanisms.

Adolescent↗

PubMed2006

Yearlong physical activity and depressive symptoms in older Japanese adults: cross-sectional data from the Nakanojo study.

OBJECTIVE: The objective of this study was to investigate associations between accelerometer measurements of physical activity and psychosocial variables in older people. METHODS: Subjects were 184 Japanese aged 65-85 years. An accelerometer provided step count and physical activity intensity data throughout each 24-hour period for 1 year. At the end of the year, anxiety, depression, and cognitive function were assessed. RESULTS: Controlling for age, the daily number of steps, and the daily duration of moderate-intensity physical activity showed significant negative correlations with depressive mood. CONCLUSION: A depressive mood is associated with the quantity and quality of habitual physical activity.

Aged↗

PubMed2005

Cerebral glucose metabolism associated with a fear network in panic disorder.

The present study was performed to assess cerebral glucose metabolism in patients with panic disorder using positron emission tomography. F-fluorodeoxyglucose positron emission tomography with voxel-based analysis was used to compare regional brain glucose utilization in 12 nonmedicated panic disorder patients, without their experiencing panic attacks during positron emission tomography acquisition, with that in 22 healthy controls. Panic disorder patients showed appreciably high state anxiety before scanning, and exhibited significantly higher levels of glucose uptake in the bilateral amygdala, hippocampus, and thalamus, and in the midbrain, caudal pons, medulla, and cerebellum than controls. These results provided the first functional neuroimaging support in human patients for the neuroanatomical hypothesis of panic disorder focusing on the amygdala-based fear network.

Adult↗

PubMed2005

Explicit knowledge and intention to learn in sequence learning: an event-related potential study.

The present study was performed to examine how intention to learn and explicit knowledge in sequence learning are reflected in event-related potentials. Participants responded to numerals presented in a repeating order, which were replaced infrequently by deviant numerals. The participants were given incidental or intentional learning instructions. Sequence parts for which they acquired explicit knowledge were identified for each participant by post-task memory tests. Reaction times indicated that sequence learning occurred under both types of instruction. The N2 enhancement for deviants was primarily associated with explicit sequence knowledge, and the P3 enhancement showed a weak association. These results suggested that N2 and P3 reflect different aspects of explicit learning.

Adolescent↗

PubMed2005

Effects of value and reward magnitude on feedback negativity and P300.

Feedback negativity is a negative component of the event-related brain potential observed 250-300 ms after feedback stimuli. The present study investigated the effects of value (correct or incorrect) and reward magnitude (no, small or large) on feedback negativity and P300. Feedback negativity was larger after incorrect feedback than after correct feedback, irrespective of reward magnitude. In contrast, P300 amplitude increased with reward magnitude, irrespective of value. The amplitude of feedback negativity was correlated with a trait score of negative affect and not positive affect, whereas P300 amplitude was correlated with positive affect and not negative affect. These results suggest that value and reward magnitude are processed separately in the brain.

Adult↗

PubMed2005

Possible interactive effects of demographic factors and stress coping mechanisms on depression and anxiety in maintenance hemodialysis patients.

OBJECTIVE: The aim of this study was to assess the possible interactive effects of age, sex, duration of hemodialysis (HD), educational and income levels, and stress coping mechanisms on depression and anxiety in patients on maintenance HD. METHODS: Uremic patients (N=416), regularly undergoing HD for more than 1 year, who did not have apparent cerebrovascular disease or serious intellectual impairment, were investigated. The interactive effects of age, sex, duration of HD, and educational and income levels, in relation to stress coping mechanisms, on depression or anxiety were assessed by hierarchical multiple regression analyses. RESULTS: Regression lines illustrating significant (P<.05) interactions were constructed. The decrease in depression accompanying the increase in task-oriented stress coping was greater in highly educated patients than it was in the other patients. Anxiety levels decreased when patients had both high income and demonstrated a range of task-oriented stress coping mechanisms. For patients undergoing HD for long duration, or with a relatively high income, the decrease of depression and anxiety accompanying a decrease of emotion-oriented stress coping was greater, as compared with other patients. The decrease of depression accompanying an increase of avoidance-oriented stress coping was greater in patients with low income and in older patients than it was in the other patients. CONCLUSIONS: These findings may lead to the development of specific and focused interventions for depression or anxiety in maintenance HD patients.

Adaptation, Psychological↗

PubMed2005

Harmony seeking and the risk of prostate cancer: a prebioptic study.

OBJECTIVE: This semiprospective case-control study was performed to investigate the relationship between harmony-seeking personality and the occurrence of prostate cancer. METHODS: Out of 217 consecutive participants admitted to hospital for biopsy, 86 and 81 were classified into the case and control groups, respectively, based on their initial diagnosis and eligibility criteria. The participants answered several questionnaires after admission. The logistic regression model was used for multivariate analyses to assess the association. RESULTS: "Harmony-seeking personality" was selected as the only psychological variable significantly contributing to the model, while "family history of prostate cancer" as the only somatic variable. "Harmony-seeking" maintained a significant contribution to the model, also including "family history" and even to the model adjusted by "patient prediction of cancer diagnosis" and "prostate-specific antigen" (PSA), probably related to the consequences of the disease. CONCLUSION: The harmony-seeking personality could differentiate between groups of men with and without prostate cancer.

Affect↗

PubMed2005

A placebo-controlled, randomized withdrawal study of sertraline for panic disorder in Japan.

The objective of this double-blind, placebo-controlled randomized withdrawal study was to evaluate the efficacy and safety of sertraline for 8 weeks in treating Japanese patients with DSM-IV panic disorder. Patients (n=394) were initially treated with 8 weeks of open-label sertraline followed by 8 weeks of double-blind treatment with either sertraline (50-100 mg/day) or placebo. Responders during the open-label phase were eligible to be entered into the double-blind phase. Two hundred and forty patients were entered to the double-blind phase and randomly assigned to receive sertraline (n=119) or placebo (n=121). On the primary efficacy measure (relapse), there was no significant difference between the two treatment groups (sertraline 10.1%; placebo 13.2%). However, the frequency of panic attacks was significantly (P=0.012) lower for sertraline compared to placebo. The proportion of sertraline-treated patients who met response criteria (Clinical Global Impression-Improvement Scale score of 1 or 2) at the end of double-blind phase treatment was also significantly (P=0.003) higher for sertraline (89.9%) compared to placebo (74.4%). Panic Disorder Severity Scale total score was significantly (P=0.012) lower in the sertraline group compared to the placebo group. Adverse events during acute treatment were consistent with the known adverse event profile of sertraline, and the incidence of adverse events during the double-blind phase treatment was not different between sertraline and placebo.

Adult↗

PubMed2005

Hikikomori, is it a culture-reactive or culture-bound syndrome? Nidotherapy and a clinical vignette from Oman.

Hikikomori, a form of acute social withdrawal, is becoming a silent epidemic in Japan. As it has not been reported from other parts of the world, hikikomori fulfills the criteria for "a culture-bound syndrome." We report a case from Oman, in the southern part of Arabia, with all the essential features of hikikomori. We speculate that the social environment of Japanese and Omani society could reinforce behavior akin to hikikomori although this condition may also transcend geography and ethnicity.

Adult↗

PubMed2005

[Osteoporosis and stress].

There may be three ways of relationship between stress and osteoporosis. The first is that stress induces some physiological changes leading to osteoporosis. The second is that stress induces behavioral distortion of eating, drinking, exercise, and sleep habits, which leads to osteoporosis. The third is that osteoporosis, on the other hand, brings about anxiety, depression, loss of social roles, and social isolation, which leads to stress. The susceptible sex and age groups are postmenopausal women and young women. The abrupt decrease of estrogen in postmenopausal women promotes reabsorption of bone, and it was also reported that the increase of interleukin-6 (IL-6) that is downstream of estrogen was related to the production of osteoclast and to the development of disability of the aged. Regarding the association with stress, while it was reported that depression or depressive states directly increased inflammation-induced cytokines including IL-6, it was also pointed out that stress-induced easy infectious may produce chronic infection, which indirectly increases inflammation-induced cytokines. Anorexia Nervosa that is assumed to be associated with adolescent developmental stress is noteworthy in young women. Amenorrhea is always present in this disease, and in addition to bone reabsorption associated with estrogen deficiency, the decrease of bone formation associated with malnutrition may be related to the development of osteoporosis.

Adult↗

PubMed2004

Error-related negativity reflects detection of negative reward prediction error.

Error-related negativity (ERN) is a negative deflection in the event-related potential elicited in error trials. To examine the function of ERN, we performed an experiment in which two within-participants factors were manipulated: outcome uncertainty and content of feedback. The ERN was largest when participants expected correct feedback but received error feedback. There were significant positive correlations between the ERN amplitude and the rate of response switching in the subsequent trial, and between the ERN amplitude and the trait version score on negative affect scale. These results suggest that ERN reflects detection of a negative reward prediction error and promotes subsequent response switching, and that individuals with high negative affect are hypersensitive to a negative reward prediction error.

Adult↗

PubMed2004

Comorbidity of irritable bowel syndrome, panic disorder, and agoraphobia in a Japanese representative sample.

OBJECTIVES: Irritable bowel syndrome (IBS) is considered to be a transcultural functional bowel disorder with high comorbidity and psychiatric disorders; but well-designed epidemiologic studies have never been performed in Japan. The purpose of this study was to establish the prevalence of IBS, together with the comorbidity rates of panic disorder (PD) and agoraphobia, employing a large-scale survey based on stratified random sampling. METHODS: A total of 4,000 subjects aged 20-69 years completed a questionnaire and the results were weighted to ensure representativeness of the Japanese general population. The questionnaire covered key symptoms of IBS, PD, and agoraphobia. The prevalence of IBS and its subtypes was calculated by gender. The comorbidity of PD and agoraphobia with IBS was compared with morbidity in non-IBS subjects; and comorbidity in IBS subjects who had consulted medical practitioners regarding their symptoms and in those who had not was also compared. RESULTS: The prevalence of IBS was 6.1% in total. It was significantly higher in females than in males. Diarrhea-predominant IBS was more prevalent in males and constipation-predominant IBS in females. The morbidity rates of PD and agoraphobia were significantly higher in IBS than in non-IBS subjects. Comorbidity did not differ between female and male IBS subjects, while morbidity was significantly higher in female than in male non-IBS subjects; and comorbidity did not differ between consulter and nonconsulter subjects. CONCLUSIONS: The prevalence of IBS and its comorbidity with PD and agoraphobia in Japan were demonstrated to be similar to those reported in Western industrialized countries.

Adult↗

PubMed2004

Preliminary study: psychological effects of muscle relaxation on juvenile delinquents.

The purpose of this study is to test our hypothesis that muscle relaxation is effective on the psychological well-being of juvenile delinquents. Subjects were 16 juvenile delinquents who had entered a reform school. Subjects were divided into two groups. The muscle relaxation group received muscle relaxation therapy once a week for a total of 4 times. The control group spent an ordinary daily life in the reformatory. Psychological questionnaires used were the Rosenzweig Picture Frustration Study (P-F study), the Psychological Stress Response Scale (PSRS), and the Eysenck Personality Questionnaire (EPQ). There was a significant Group Time interaction of the Group Conformity Rating (GCR) of the P-F study (F [1,14] =10.1, P=0.007). There were no significant interactions in the other psychological subscales. Thus, muscle relaxation therapy may improve frustration tolerance among juvenile delinquents.

Adaptation, Psychological↗

PubMed2004

Laterality and imbalance of muscle stiffness relate to personality.

The authors' purpose in this study was to test the hypothesis that laterality and imbalance of muscle stiffness relate to personality. The authors selected 23 healthy volunteers and divided them into two groups based on the predominance of muscle stiffness on the left or right side. Imbalance of muscle stiffness was calculated as the absolute value of the difference of muscle stiffness between the right and left sides. The authors evaluated personality with the Japanese version of the Eysenck Personality Questionnaire. Subjects with left predominant muscle stiffness of the rectal abdominis had significantly higher neuroticism score than those with right predominant muscle stiffness. Subjects with more imbalance of muscle stiffness in the latissimus dorsi and in the trapezius had significantly higher neuroticism and psychoticism scores than those with less imbalance. The findings suggest that laterality and imbalance of muscle stiffness relate to personality.

Adult↗