Yuan-Hwa Chou

Taipei Veterans General Hospital, T’ai-pei, Taipei, Taiwan

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Publications (62)

  • Yuan-Hwa Chou · Jiing-Feng Lirng · Wen-Chi Hsieh · [...] · Shyh-Jen Wang
    [Show abstract] [Hide abstract] ABSTRACT: Converging evidence indicates the hypothalamus-pituitary-adrenal axis and serotonergic neurons exert reciprocal modulatory actions. Likewise, brain-derived neurotrophic factor (BDNF) has been implicated as a growth and differentiation factor in the development of serotonergic neurons. The aim of this study was to examine the interaction of cortisol and BDNF on serotonin transporter (SERT) in bipolar disorder (BD). Twenty-eight BD and 28 age- and gender-matched healthy controls (HCs) were recruited. (123)I-ADAM with single-photon emission computed tomography (SPECT) was applied for measurement of SERT availability in the brain, which included the midbrain, thalamus, putamen and caudate. Ten milliliters of venous blood was withdrawn, when the subject underwent SPECT, for the measurement of the plasma concentration of cortisol and BDNF. SERT availability was significantly decreased in the midbrain and caudate of BD compared with HCs, whereas plasma concentration of cortisol and BDNF did not show a significant difference. The linear mixed-effect model revealed that there was a significant interaction of group and cortisol on SERT availability of the midbrain, but not BDNF. Linear regression analyses by groups revealed that cortisol was associated with SERT availability in the midbrain in the HCs, but not in BD. Considering previous studies, which showed a significant association of cortisol with SERT availability in the HCs and major depressive disorder (MDD), our result replicated a similar finding in HCs. However, the negative finding of the association of cortisol and SERT availability in BD, which was different from MDD, suggests a different role for cortisol in the pathophysiology of mood disorder.
    Article · Dec 2015 · European neuropsychopharmacology: the journal of the European College of Neuropsychopharmacology
  • Yuan-Hwa Chou · Wen-Chi Hsieh · Li-Chi Chen · [...] · Shyh-Jen Wang
    [Show abstract] [Hide abstract] ABSTRACT: Background: Reduced brain serotonin transporter (SERT) has been demonstrated in bipolar disorder (BD). The aim of this study was to explore the potential role of cytokines on reduced SERT in BD. Methods: Twenty-eight BD type I patients and 28 age- and gender-matched healthy controls (HCs) were recruited. Single photon emission computed tomography with the radiotracer 123I ADAM was used for SERT imaging. Regions of interest included the midbrain, thalamus, putamen and caudate. Seven cytokines, including tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), interleukin-1α (IL-1α), IL-1β, IL-4, IL-6 and IL-10, were measured using an enzyme linked immune-sorbent assay. Results: SERT availability in the midbrain and caudate was significantly lower in BD compared to HCs. IL-1β was significantly lower, whereas IL-10 was significantly higher in BD compared to HCs. Multiple linear regression analyses revealed that there were associations between cytokines, IL-1α, IL-1β, IL-6 and SERT availability in the midbrain but not in the thalamus, putamen and caudate. Furthermore, linear mixed effect analyses demonstrated that these associations were not different between HCs and BD. Conclusion: While many cytokines have been proposed to be important in the pathophysiology of BD, our results demonstrated that significant associations between cytokines and SERT availability may explain the role of cytokines in mood regulation. However, these associations were not different between HCs and BD, which imply the role of these cytokines is not specific for BD.
    Article · Nov 2015 · Journal of Affective Disorders
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    [Show abstract] [Hide abstract] ABSTRACT: Introduction. Benzodiazepines (BZDs) and zolpidem, zopiclone, and zaleplon (Z-drugs) are commonly prescribed to HIV-infected patients. We hypothesized that frequent BZD and Z-drug use among these patients may be associated with psychiatric illnesses, particularly in long-term users. Methods. We included 1,081 patients with HIV between 1998 and 2011 from the Taiwan National Health Insurance Research Database and matched them according to age, sex, and comorbidity with uninfected controls to investigate the psychiatric diagnoses and prescriptions of BZDs and Z-drugs. Cumulative defined daily dose (cDDD) was assessed as the indicator of the duration of medication exposure. Patients exhibiting a cDDD exceeding 180 were defined as long-term users. Results. The patients with HIV had an increased risk of any use (odds ratio (OR): 8.70, 95% confidence interval (CI): 6.82-10.97) and long-term use (OR: 5.06, 95% CI: 3.63-7.04) of BZD and Z-drugs compared with those without HIV during the follow-up after demographic data and psychiatric comorbidities were adjusted. Conclusion. A large proportion of the HIV-infected patients received prescriptions of BZDs and Z-drugs. Mood disorders, insomnia, anxiety disorders, HIV infection, and substance use disorder were substantial predictors among the BZD and Z-drug users. These findings suggest that providing psychiatric services for HIV-infected patients is vital.
    Full-text Article · Jan 2015 · BioMed Research International
  • Kai-Chun Yang · Shyh-Jen Wang · Wen-Chi Hsieh · [...] · Yuan-Hwa Chou
    [Show abstract] [Hide abstract] ABSTRACT: Suicide with charcoal burning, which results in carbon monoxide (CO) poisoning, is common in Asia. This study was designed to elucidate associations between changes in the dopamine transporter (DAT) and cognitive function in patients following CO poisoning during a follow-up period of 6 months. Participants comprised 31 healthy controls (HCs) and 21 CO poisoning patients. Each subject underwent single photon emission computed tomography with [(99m)Tc] TRODAT-1 to measure DAT availability and completed a cognitive battery assessing attention, memory, and executive function. For CO poisoning patients, a second DAT measurement and repeated cognitive evaluations were performed 6 months later. At baseline, DAT availability over bilateral striatum in CO poisoning subjects was significantly lower than in HCs. After 6 months, there was no significant change of DAT availability in CO poisoning patients. CO poisoning patients also had worse cognitive performance in all domains compared with HCs at baseline. After 6 months, most cognitive functions were significantly improved, except for the Wisconsin Card Sorting Test (WCST), a measure of executive function. Interestingly, changes in the WCST were significantly correlated with changes in DAT availability during the 6-month follow-up period. The persistence of reduced DAT availability and its association with impaired performance on the WCST indicate a crucial role of DAT in the recovery of executive function following CO poisoning. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.
    Article · Dec 2014 · Psychiatry Research: Neuroimaging
  • Yueh-Ching Chou · Fan-Hsiu Chao · Yuan-Hwa Chou
    Article · Mar 2014 · Journal of the Formosan Medical Association
  • Ju-Wei Hsu · Jiing-Feng Lirng · Shyh-Jen Wang · [...] · Yuan-Hwa Chou
    [Show abstract] [Hide abstract] ABSTRACT: The serotonin hypothesis plays a critical role in the etiology of bipolar disorder (BD). Although many studies have demonstrated reciprocal relationships between serotonin metabolism and immune-inflammatory pathways that occur in depression, studies linking serotonergic function and cytokines are still limited concerning BD. The aim of this study was to investigate the interaction of brain serotonin transporter (SERT) and cytokines in BD. Twenty patients with euthymic BD and 20 age- and sex-matched healthy controls (HC) were recruited. Single photon emission computed tomography with the radiotracer (123) I-ADAM was used for the SERT imaging. The specific uptake ratio, which represents SERT availability, was the primary measured outcome. Cytokines included the pro-inflammatory cytokine tumor necrosis factor-α (TNF-α) and the anti-inflammatory cytokine interleukin-10 (IL-10). Cytokine concentration was measured using an enzyme-linked immunosorbent assay. SERT availability was significantly lower in the midbrain and caudate of patients with BD compared with HC, but not in the thalamus and putamen. IL-10 was significantly higher, whereas TNF-α was not different in euthymic patients with BD compared with HC. There was a significant association of SERT availability and IL-10 in the thalamus, but not in the midbrain, caudate, or putamen. Our results demonstrate the interaction of SERT availability and IL-10 in euthymic BD. This result may further explain the role of SERT and cytokines in the etiology of BD.
    Article · Dec 2013 · Bipolar Disorders
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    Yuan-Hwa Chou · Chih-Ken Chen · Shyh-Jen Wang · [...] · Chia-Chieh Chen
    [Show abstract] [Hide abstract] ABSTRACT: The S-allele of functional polymorphisms of the serotonin transporter (SERT) gene has been demonstrated to have lower transcriptional activity compared with the L-allele, which shows low expression of SERT in the brain. However, this finding cannot be consistently replicated in vivo. The aim of this study was to determine the availability of SERT based on SERT genotype. We also examined the relationship between brain-derived neurotrophic factor (BDNF) and the availability of SERT. Sixty-two healthy subjects were recruited. Each subject underwent single-photon emission computed tomography with I-ADAM (I-labeled 2-([2-({dimethylamino}methyl)phenyl]thio)-5-iodophenylamine) for imaging SERT in the brain. The specific uptake ratio was measured, and venous blood was drawn when the subject underwent single-photon emission computed tomography to evaluate BDNF levels and SERT genotype. All subjects expressed SERT genotypes that were consistent with a biallelic model, and 26 subjects had SERT genotypes that were consistent with a triallelic model. No differences in specific uptake ratio were detected in the midbrain, putamen, caudate, and thalamus based on the SERT genotype using the biallelic and triallelic models. Interestingly, The Pearson correlation coefficient revealed a positive correlation between BDNF and SERT availability. In particular, this relationship was observed in homozygous S-allele expression and a genotype with low functional expression (SaSa/SaLg) in the biallelic and triallelic models of SERT genotypes, respectively. This finding might explain why the SS genotype of SERT did not increase the risk of major depressive disorder in Asian populations and implicate an important role of BDNF in the patients, who has the SS genotype of the SERT gene.
    Full-text Article · Apr 2013 · Journal of clinical psychopharmacology
  • Yuan-Hwa Chou · Bang-Hung Yang · Ju-Wei Hsu · [...] · Shin-Min Lee
    [Show abstract] [Hide abstract] ABSTRACT: To study the impact of video game playing on the human brain, the effects of two video games playing on cerebral blood flow (CBF) in young adults were determined. Thirty healthy subjects comprising 18 males and 12 females who were familiar with video game playing were recruited. Each subject underwent three sessions of single photon emission computed tomography (SPECT) with a bolus injection of 20mCi (99m)Tc ECD IV to measure their CBF. The first measurement was performed as baseline, the second and third measurements were performed after playing two different video games for 30min, respectively. Statistic parametric mapping (SPM2) with Matlab 6.5 implemented on a personal computer was used for image analysis. CBF was significantly decreased in the prefrontal cortex and significantly increased in the temporal and occipital cortices after both video games playing. Furthermore, decreased CBF in the anterior cingulate cortex (ACC) which was significantly correlated with the number of killed characters was found after the violent game playing. The major finding of hypo-perfusion in prefrontal regions after video game playing is consistent with a previous study showing reduced or abnormal prefrontal cortex functions after video game playing. The second finding of decreased CBF in the ACC after playing the violent video game provides support for a previous hypothesis that the ACC might play a role in regulating violent behavior.
    Article · Nov 2012
  • Yuan-Hwa Chou · Chun-Lung Lin · Shyh-Jen Wang · [...] · Mei-Hsiu Liao
    [Show abstract] [Hide abstract] ABSTRACT: BACKGROUND: Aggression is frequently observed in patients diagnosed with bipolar disorder (BD). Previous studies found a negative association between aggression and serotoninergic function in patients with BD, as well as in healthy subjects. The objective of this study was to determine whether there is an association between aggression and the availability of the serotonin transporter (SERT) in euthymic BD II patients. METHODS: Thirty-eight age-matched healthy controls (HCs) and 24 BD II patients were recruited. BD II patients were under stable treatment in the euthymic state. The Overt Aggression Scale (OAS) was used for the assessment of aggression. Single photon emission computed tomography with (123)I-ADAM was used for SERT imaging. A specific uptake ratio, which represents availability, was the primary measured outcome. RESULTS: The total OAS scores, as well as the scores on all of the sub-items, were significantly higher in BD II patients than in the HCs group. There was no significant difference in SERT availability between BD II and HCs subjects in different brain regions. The Pearson's correlation between the total OAS scores and the sub-item aggression and SERT availability was significant. LIMITATION: The OAS was used for the assessment of the past week of the patients' condition and thus did not reflect their trait status. CONCLUSIONS: The higher total scores of OAS in euthymic BD II patients than in HCs support the idea that aggression might be a trait marker for BD. Although SERT availability in euthymic BD II patients and in HCs did not differ significantly, the correlation of SERT availability and total OAS provides the possible explanation of aggression in BD II.
    Article · Nov 2012 · Journal of Affective Disorders
  • Yuan-Hwa Chou · Shyh-Jen Wang · Jiing-Feng Lirng · [...] · Mei-Hsiu Liao
    [Show abstract] [Hide abstract] ABSTRACT: BACKGROUND: Studies have proposed that cognitive deficits are present in a variety of mood states in bipolar disorder (BD). The goal of this study was to find the cognitive deficits in euthymic BD patients and to further explore possible underlying mechanisms of the deficits. METHODS: Thirty-three healthy controls (HCs) and twenty-three euthymic BD type I patients were recruited. Single photon emission computed tomography (SPECT) with (123)I-ADAM was used to image the serotonin transporter (SERT). Ten milliliters of venous blood was drawn for the measurement of brain derived neurotrophic factor (BDNF). Cognitive functions were tested included attention, memory, and executive function. RESULTS: We found that the SERT availability in both the midbrain and striatal regions was decreased in the BD patients compared with the HCs; however, the BDNF were not different between the two groups. There was no correlation between the SERT availability and the BDNF. Interestingly, there were statistically significant differences in sub-items of the facial memory test and the Wisconsin Card Sorting Test between the BD patients and the HCs, which showed that there was a cognitive deficit in the BD patients. However, the overall deficits in cognition were not significantly correlated with the SERT availability or the BDNF. LIMITATION: The effect of medications on cognitive function and BDNF should be considered. CONCLUSIONS: We replicated previous findings that showed cognitive deficits in euthymic BD patients. However, the underlying mechanism of cognitive deficits in euthymic BD patients cannot be entirely explained by SERT and BDNF.
    Article · Aug 2012 · Journal of Affective Disorders
  • Chin-Bin Yeh · Yuan-Hwa Chou · Cheng-Yi Cheng · [...] · Wen-Sheng Huang
    [Show abstract] [Hide abstract] ABSTRACT: Single photon emission computed tomography (SPECT) with Tc-99m TRODAT-1 as ligand can be used to evaluate striatal dopamine transporters (DAT) in young subjects. The purpose of this study was to evaluate the reproducibility of (99m)Tc-TRODAT-1 SPECT in DAT binding in healthy young men. Fourteen healthy young men were recruited. The test-retest studies were performed 1week apart. Specific uptake ratios (SUR) of the striatum (ST) and its subregions, the caudate (CA) and the putamen (PU), were measured using the occipital cortex as the reference tissue. The reliability of the two measurements between test and retest, showed significant correlations for the ST, CA and PU, was demonstrated by calculating the intraclass correlation coefficient (ICC). Thus, (99m)Tc-TRODAT-1 SPECT might provide a reproducible and reliable tool in clinical management of young patients with DAT-related disorders.
    Article · Apr 2012 · Psychiatry Research
  • Yang-Ching Lo · Yuan-Hwa Chou · Hsiang-Yu Yu
    Article · Mar 2012 · Sleep Medicine
  • [Show abstract] [Hide abstract] ABSTRACT: The goals of the meta-analysis were to investigate the overall effectiveness of cognitive behavioral group therapy (CBGT) for depression and relapse prevention in depression from 2000 to 2010, and to investigate how the variables (episode, residual symptoms, group size, control group, group manual, therapist experience, therapy frequency, session length, and take-home assignment) of a CBGT study could affect the effect size. This study collected actual study designs sought of CBGT for depression published from 2000 to 2010. These studies were then cross-referenced using Medical Subject Headings (MeSH) with the following keywords: group therapy, cognitive therapy, cognitive behavioral therapy, cognitive behavioral group therapy, psychotherapy, depression, relapse, and recurrence. The quality of the studies was evaluated using Cochrane Collaboration Guidelines. The effect size of CBGT on depression and relapse prevention in depression used the formula devised by Hedges and Olkin (1985). The study investigated the results of 32 studies on the effect of CBGT for depression. The CBGT had an immediate (g=-0.40) and continuous effect over 6 months (g=-0.38), but no continuous effect after 6 months (g=-0.06). The CBGT lowered the relapse rate of depression (RD = 0.16). Variables significantly different from each other in terms of immediate effect were: CBGT versus usual care, therapy sessions lasting longer than 1 hour, and take-home assignments. Preintervention severity of depression and patient turnover rate were found to be significantly related to the size of the immediate effect. The relapse rate after 6 months was significantly related only to "participants have no residual symptoms/participants did not mention residual symptoms." Researchers and clinicians should take note that CBGT had a moderate effect on the level of depression and a small effect on the relapse rate of depression. The results of this study suggest that the patient should receive a course of therapy at least every 6 months.
    Article · Feb 2012 · Worldviews on Evidence-Based Nursing
  • Ju-Wei Hsu · Shyh-Jen Wang · Chun-Lung Lin · [...] · Yuan-Hwa Chou
    [Show abstract] [Hide abstract] ABSTRACT: Previous brain imaging studies have demonstrated a seasonal difference of serotonin transporter (SERT) binding in the human brain. However, the results were somewhat contradictory. We conducted test-retest study with single photon emission computed tomography (SPECT) with ¹²³I-ADAM as ligand in 28 healthy subjects. Ten of the subjects were studied within 1 month, whereas 18 were randomly assigned to be studied over a period of up to 1 year. The primary measure was the specific uptake ratio (SUR). Regions of interest included the midbrain, thalamus, putamen and caudate. The intra-class correlation coefficient (ICC) was 0.52-0.94 across different brain regions over 1 month, whereas the ICC was -0.24-0.63 over a 1-year period. The 1-month variability ranged from 6.5 ± 5.1% to 12.5 ± 10.6% across different brain regions, and the 1-year variability ranged from 16.5 ± 9.6% to 41.9 ± 35.5%. The Kruskal-Wallis test revealed a significant difference of variability across months. The Wilcoxon Signed Ranks Test showed the SUR between test-retest scans was of borderline significance. Curve fitting, using a 4th degree polynomial model, revealed a significant circadian correlation between the variability and interval of test-retest measurements. Our findings demonstrate the test-retest reproducibility of ¹²³I-ADAM in different time periods and suggest that circadian variation of SERT levels in the human brain might exist.
    Article · Nov 2011 · Psychiatry Research
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    Kai-Chun Yang · Hsiao-Lun Ku · Chia-Liang Wu · [...] · Yuan-Hwa Chou
    [Show abstract] [Hide abstract] ABSTRACT: Carbon monoxide poisoning (COP) after charcoal burning results in delayed neuropsychological sequelae (DNS), which show clinical resemblance to Parkinson's disease, without adequate predictors at present. This study examined the role of dopamine transporter (DAT) binding for the prediction of DNS. Twenty-seven suicide attempters with COP were recruited. Seven of them developed DNS, while the remainder did not. The striatal DAT binding was measured by single photon emission computed tomography with (99m)Tc-TRODAT. The specific uptake ratio was derived based on a ratio equilibrium model. Using a logistic regression model, multiple clinical variables were examined as potential predictors for DNS. COP patients with DNS had a lower binding on left striatal DAT binding than patients without DNS. Logistic regression analysis showed that a combination of initial loss of consciousness and lower left striatal DAT binding predicted the development of DNS. Our data indicate that the left striatal DAT binding could help to predict the development of DNS. This finding not only demonstrates the feasibility of brain imaging techniques for predicting the development of DNS but will also help clinicians to improve the quality of care for COP patients.
    Full-text Article · Oct 2011 · Psychiatry Research
  • Yuan-Hwa Chou · Shyh-Jen Wang · Chun-Lung Lin · [...] · Mei-Hsiu Liao
    Article · Sep 2011 · International Clinical Psychopharmacology
  • Ju-Wei Hsu · Tung-Ping Su · Chen-Ying Huang · [...] · Yuan-Hwa Chou
    [Show abstract] [Hide abstract] ABSTRACT: Several previous studies, including a meta-analysis, reported no significant differences between various selective serotonin reuptake inhibitors (SSRIs) in the treatment of major depressive disorder. However, because of the different chemical structure of SSRIs and the difference in the frequency of serotonin transporter polymorphisms between ethnic groups, a head-to-head comparative study between SSRIs in different populations may be enlightening. We compared the efficacy and adverse effect profiles of citalopram and sertraline in a double-blinded randomized clinical trial in a Chinese population of drug-naïve patients with first-episode major depressive disorder. Fifty-one patients were randomly assigned to citalopram or sertraline treatment. The Montgomery-Åsberg Depression Rating Scale (MADRS) was used as the primary outcome. Efficacy and adverse effects were analyzed in an intent-to-treat population. Efficacy was analyzed using a last-observation-carried-forward method for early terminators. There were no significant differences in demographic characteristics at baseline. No significant differences were found in MADRS scores between citalopram and sertraline at baseline (36.6 ± 5.5 vs 38.2 ± 4.9; P = 0.322) or at the end of treatment (week 6; 10.8 ± 10.0 vs 16.7 ± 11.3; P = 0.082). However, MADRS scores in the citalopram group were significantly lower at week 1 (25.2 ± 8.5 vs 30.4 ± 6.1; P = 0.029) and week 3 (15.9 ± 10.0 vs 22.1 ± 8.7; P = 0.037). Overall, treatment-emergent adverse effects were reported by 14.3% and 28.6% of patients in the citalopram and sertraline groups, respectively. In conclusion, citalopram and sertraline were both efficacious and well tolerated. However, citalopram exhibited a significantly faster onset than sertraline during the early weeks of treatment and tended to have a better efficacy in overall treatment, although the statistic was not significant.
    Article · Aug 2011 · Journal of clinical psychopharmacology
  • [Show abstract] [Hide abstract] ABSTRACT: The level of serotonin was regulated by serotonin transporter (SERT), which is a decisive protein in regulation of serotonin neurotransmission system. Many psychiatric disorders and therapies were also related to concentration of cerebral serotonin. I-123 ADAM was the novel radiopharmaceutical to image SERT in brain. The aim of this study was to measure reliability of SERT densities of healthy volunteers by automated anatomical labeling (AAL) method. Furthermore, we also used statistic parametric mapping (SPM) on a voxel by voxel analysis to find difference of cortex between test and retest of I-123 ADAM single photon emission computed tomography (SPECT) images.Twenty-one healthy volunteers were scanned twice with SPECT at 4h after intravenous administration of 185MBq of 123I-ADAM. The image matrix size was 128×128 and pixel size was 3.9mm. All images were obtained through filtered back-projection (FBP) reconstruction algorithm. Region of interest (ROI) definition was performed based on the AAL brain template in PMOD version 2.95 software package. ROI demarcations were placed on midbrain, pons, striatum, and cerebellum. All images were spatially normalized to the SPECT MNI (Montreal Neurological Institute) templates supplied with SPM2. And each image was transformed into standard stereotactic space, which was matched to the Talairach and Tournoux atlas. Then differences across scans were statistically estimated on a voxel by voxel analysis using paired t-test (population main effect: 2 cond's, 1 scan/cond.), which was applied to compare concentration of SERT between the test and retest cerebral scans.The average of specific uptake ratio (SUR: target/cerebellum-1) of 123I-ADAM binding to SERT in midbrain was 1.78±0.27, pons was 1.21±0.53, and striatum was 0.79±0.13. The cronbach's α of intra-class correlation coefficient (ICC) was 0.92. Besides, there was also no significant statistical finding in cerebral area using SPM2 analysis. This finding might help us to understand reliability of I-123 ADAM SPECT imaging and further develop new strategy for the treatment of psychiatric disorders.
    Article · Aug 2011 · Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment
  • Chien-Kuan Chiang · Yuan-Hwa Chou · Ying-Hseuh Chen · [...] · Chih-Sung Liang
    [Show abstract] [Hide abstract] ABSTRACT: Bupropion, a dual norepinephrine and dopamine reuptake inhibitor, has been approved by the United States Food and Drug Administration for the treatment of major depressive disorder. The most common treatment-emergent adverse events reported with bupropion were headache, dry mouth, nausea and agitation. The following is a case report intended to draw attention to a rarely reported adverse effect of bupropion. This article describes a female adolescent with depression who developed aphthous ulcers while on high-dose bupropion with positive rechallenge. This is the first case report indicating the incidence of aphthous ulcers associated with bupropion treatment.
    Article · Jul 2011 · General hospital psychiatry
  • [Show abstract] [Hide abstract] ABSTRACT: The objective of this study was to use a mixture of Poisson (MOP) model expectation maximum (EM) algorithm for segmenting microPET images. Simulated rat phantoms with partial volume effect and different noise levels were generated to evaluate the performance of the method. The partial volume correction was performed using an EM deblurring method before the segmentation. The EM-MOP outperforms the EM-MOP in terms of the estimated spatial accuracy, quantitative accuracy, robustness and computing efficiency. To conclude, the proposed EM-MOP method is a reliable and accurate approach for estimating uptake levels and spatial distributions across target tissues in microPET (11)C-raclopride imaging studies.
    Article · Jul 2011 · Computerized medical imaging and graphics: the official journal of the Computerized Medical Imaging Society