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Biomedical subjects

Po See Chen

Publications and source records attributed to Po See Chen.

At least 19 recordsLinked to original sources
PubMed2006

White matter and subcortical gray matter lesion volume changes and late-life depression outcome: a 4-year magnetic resonance imaging study.

BACKGROUND: Cross-sectional studies have shown that late-onset depression is associated with larger deep white matter lesions (WMLs) and subcortical gray matter lesions (GMLs). In a longitudinal analysis, we examined changes in deep WMLs and subcortical GMLs in older depressed and nondepressed subjects over a 4-year period. METHODS: Brain magnetic resonance imaging (MRI) scans were obtained on 164 depressed and 126 healthy subjects aged 60 years or older at baseline, and 2 and 4 years after recruitment. WMLs and GMLs were measured using a semiautomated technique. We used repeated-measures analysis of covariance to determine cross-sectional lesion volume differences, whether lesion volume changes differed between patients and controls, and the effect of lesion volume changes on outcome in late-life depression. RESULTS: Mean volumes of lesions for the depressive group were 6.51, 8.18 and 7.75 cm2 for WMLs and 0.23, 0.30 and 0.34 cm2 for GMLs at baseline, 2-year and 4-year follow-up, respectively. Mean volumes of lesions for the control group were 4.83, 6.22 and 6.45 cm2 for WMLs and 0.17, 0.25 and 0.23 cm2 for GMLs at baseline, 2-year and 4-year follow-up, respectively. Cross-sectional between-group mean lesion volumes were significantly different for each measure. However, the pattern of WML and GML volume changes over time was not significantly different between groups. Treatment outcome was associated with changes in total and white matter lesion volume over time. CONCLUSIONS: Lesion volume progression is associated with aging and the pathological condition of late-life depression. The mechanisms that produce these progressive lesion changes remain unclear. Treatments aimed at arresting lesion progression may play a role in the management of late-life depression.

Aged↗
PubMed2006

Different dimensions of social support for the caregivers of patients with schizophrenia: main effect and stress-buffering models.

The aims of this study were: (i) to assess the impact of caring for patients with schizophrenia on the mental health status of the caregivers; and (ii) to examine the direct and buffer effects of social support on the mental health status of these caregivers. A total of 61 key caregivers of patients with schizophrenia were administered the Chinese Health Questionnaire (CHQ) and the Measure of Support Function (MSF) self-report questionnaire to assess their mental health and social support status. The MSF questionnaire constitutes four subscales, including: (i) the perceived crisis support (PCS); (ii) the perceived routine support (PRS); (iii) the received crisis support (RCS); and (iv) the received routine support (RRS) subscale. The Positive and Negative Syndrome Scale (PANSS) was used to assess the psychopathology severity of the patients they cared for. Then the authors used the hierarchical multiple regression model to analyze the relationship between these variables. The psychopathology severity of the patients reflected by the PANSS scores correlated inversely with the caregivers' CHQ scores. Besides, the PCS subscale scores correlated positively with the caregivers' CHQ scores. Moreover, the interaction between the RCS subscale scores and the PANSS scores was significant. Significant positive correlation between the RCS and CHQ exists only in the higher PANSS subgroup, but not in the lower PANSS subgroup. The psychopathological severity of the patients has a negative impact on their caregivers' mental health. PCS has a direct effect, and RCS has a buffer effect on the mental health status of these caregivers.

Adult↗
PubMed2005

The correlation between striatal dopamine D2/D3 receptor availability and verbal intelligence quotient in healthy volunteers.

BACKGROUND: Although a correlation between the central dopaminergic system and intelligence may exist, the results from imaging studies remain inconclusive. The aim of this study was to explore the relationship between striatal dopamine D2/D3 receptor availability and verbal intelligence quotient (VIQ) using single photon emission computed tomography (SPECT). METHOD: Striatal D2/D3 receptor availability of 64 healthy subjects was determined with the [123I]iodobenzamide ([123I]IBZM) ligand. Intelligence quotients (IQs) of the subjects were measured by the Wechsler Adult Intelligence Scale--Revised (WAIS-R). RESULTS: In addition to age, left striatal D2/D3 receptor availability correlated positively with VIQ. In females, left striatal D2/D3 receptor availability was the only variable that correlated significantly with the similarities subtest of VIQ. CONCLUSIONS: There is a relationship between left striatal D2/D3 receptor availability and verbal intelligence, which varies, predominantly in males.

Adult↗
PubMed2005

Striatal dopamine D2/D3 receptor availability in male smokers.

It has been reported that the activation of the nicotine receptor evokes central endogenous dopamine release. However, whether smoking affects striatal dopamine D(2)/D(3) availability over the long run has not been well established in vivo. Fifteen male smokers and their matching controls were recruited. Striatal dopamine D(2)/D(3) receptor availability was assessed by single photon emission computed tomography with [(123)]IBZM Iodo-benzaimide. There was no significant difference in striatal D(2)/D(3) receptor availability between smokers and controls.

Adult↗
PubMed2005

The association between the Lie scale of the Maudsley personality inventory and striatal dopamine D2/D3 receptor availability of healthy Chinese community subjects.

The present study examined the relationship between the Lie scale scores and striatal D(2)/D(3) receptor availability with respect to the cerebellum in 42 healthy community volunteers in Taiwan using single photon emission computed tomography (SPECT) with [(123)I]iodo-benzoaminde (IBZM). Even after controlling of age and educational level, subjects' Lie scale scores of the Maudsley personality inventory correlate negatively with D(2)/D(3) receptor availability. Individual with higher Lie scale scores may have higher impulsivity due to lower dopaminergic availability.

Adult↗
PubMed2005

Correlation between striatal dopamine D2 receptor density and neuroticism in community volunteers.

The central dopaminergic system, as well as the central serotonergic system, has been reported to be correlated with higher neuroticism. The present study examined the relationship between striatal dopamine D(2) receptor density and neuroticism. Neuroticism was assessed with the Maudsley Personality Inventory, and psychiatric morbidity was evaluated with both the Mini International Neuropsychiatric Interview and the Hamilton Depression Rating Scale (HAM-D). Single photon emission computed tomography with [(123)I]iodo-benzamide was used to measure striatal dopamine D(2) receptor density. HAM-D scores and psychiatric morbidity in high-neuroticism individuals were higher than in low-neuroticism individuals. Moreover, striatal dopamine D(2) receptor densities were significantly correlated with the neuroticism score of the 41 subjects. The central dopaminergic system may play an important role in the neurobiological characteristics of neuroticism.

Adult↗
PubMed2005

Correlation between different memory systems and striatal dopamine D2/D3 receptor density: a single photon emission computed tomography study.

OBJECTIVE: Although studies have indicated that the human basal ganglia have a specific role in different memory systems, the functional significance of the striatal dopamine activities for the basal ganglia remains less clear. This study assessed the relationship between measures of striatal dopamine activities and indices of different memory systems in healthy individuals. METHOD: Single photon emission computed tomography and [123I]IBZM (iodobenzamide) were used to assess the striatal dopamine D2/D3 receptor density in 62 healthy volunteers aged between 19 and 61 years. All subjects underwent a Wechsler Memory Scale-Revised test. RESULTS: Dopamine D2/D3 receptor densities in the striatum decline with age. Stepwise regression analysis showed that verbal delayed recall and working memory account for most of the variance in dopamine D2/D3 measurements. These relationships remain significantly after controlling for age effects. CONCLUSIONS: Brain striatal dopamine activities are also significantly associated with various memory systems, in addition to motor functions. This may explain why patients with neuropsychiatric disorders may have both memory and motor impairments.

Adult↗
PubMed2005

Norms of performance of sustained attention among a community sample: Continuous Performance Test study.

The Continuous Performance Test (CPT) is a widely used measure of sustained attention, which is a preferred tool for assessing various mental functions. A well-established norm for CPT is essential when choosing a suitable threshold for classifying individuals as either case (CPT impairment) or non-case. The CPT performance of 900 adults who were randomly chosen from a community survey was measured to establish the norms for subgroups with different gender, age, and educational levels. The results revealed that age and educational level are significantly associated with the performance sensitivity (d') of CPT. Male subjects perform better than female subjects. Seventeen percent of the subjects scored higher on the masked CPT than on the unmasked CPT. Subjects who could not finish the masked CPT had the characteristics of older age and fewer years of education. When classifying a patient as case or non-case, his/her CPT performance should be considered relative to the norms for his/her gender, age, and educational levels.

Adult↗
PubMed2005

The relationship among insight, cognitive function of patients with schizophrenia and their relatives' perception.

Medically, insight is a multidimensional concept. Results of previous studies are inconclusive regarding the relationship between insight and global and cognitive functions. The aim of this study was to evaluate the relationship among insight, patients' global function, cognitive function of patients with schizophrenia and their key caregivers' perception about this disorder. Thirty-one patients with schizophrenia were recruited. Cognitive function such as memory index proved to be a significant predictor for patients' insight; environmental factors such as caregivers' perception was not. In addition to cognitive deficit, whether the other factors such as genetic variability, medication use, environmental factors, and illness severity, etc., could influence insight of patients will still be a controversial issue. Further multidimensional survey of the relationship with insight in a larger and comprehensive design is necessary.

Adult↗
PubMed2004

Association between cognitive performance and striatal dopamine binding is higher in timing and motor tasks in patients with schizophrenia.

The basal ganglia have received increasing attention with regard to their role in time pacing, motor function and other components of cognition. The aim of this study was to test whether the finer the motor activity and/or time perception performance were, the higher the striatal dopamine D(2) binding would be. Single photon emission computed tomography (SPECT) with [(123)I]iodobenzamide (IBZM) was performed to measure striatal D(2) receptor densities. A battery of neuropsychological tests, including the Wisconsin Card Sorting Test (WCST), the finger tapping test (FTT), and an attention test, was performed by patients with schizophrenia. Results indicated a strong correlation between the FTT score and striatal D(2) receptor binding. Neuroleptic dosage plays an important role in the relationship between cognitive tasks and striatal dopamine receptor densities. In addition, the striatal D(2) receptor density is more significantly correlated with attentional tests that consider the time effect than those that do not. Among the three tests performed, the WCST was least significantly correlated with striatal D(2) receptor densities. A decrease in striatal dopamine D(2) receptor density seems to be associated with impaired performance on optimal timing tasks and motor processing in patients with schizophrenia.

Adult↗
PubMed2004

The adjustment to illness in patients with generalized anxiety disorder is poorer than that in patients with end-stage renal disease.

Although generalized anxiety disorder (GAD) is associated with significant occupational disability, it has, however, received little attention with regard to adjustment to illness. Subjects included 102 chronic dialysis (CD) patients, 58 kidney transplant (KT) patients, and 42 GAD patients. The evaluations included the Psychosocial Adjustment to Physical Illness Scale (PAIS), the Hamilton Anxiety Rating Scale (HAM-A) and the Hamilton Depression Rating Scale (HAM-D). Preanxiolytic treatment GAD patients had the most anxiety and depressive symptoms, followed by CD patients and KT patients. KT patients and anxiolytic-treated GAD patients showed similar anxiety and depressive symptoms. These two groups were both better than CD patients. However, the adjustment to illness of GAD patients after treatment is still worse than the other two groups (108.0+/-16.3(GAD), 102.0+/-14.5(CD), 81.4+/-22.2(KT); P<.001). The CD patients had a high rate of psychiatric morbidity and a low rate of psychiatric intervention (3%); however, end-stage renal disease (ESRD) patients received only one assessment while the GAD group received two in this study. In light of the chronicity of GAD, pharmacological treatment is not sufficient by itself. Clinicians should keep these in mind when treating either GAD or ESRD.

Adaptation, Psychological↗
PubMed2004

Correlation between scores on Continuous Performance Test and plasma concentration for schizophrenic patients on risperidone.

The purpose of the present paper was to evaluate the relationship between plasma antipsychotics concentration and cognitive task performance. This may provide valuable information for rational dosage titration. Literature on the relationship between plasma risperidone (RIS) concentration and performance on the Continuous Performance Test (CPT) remains scarce. Ten patients (four male, six female) were given RIS for more than 1 year. Steady-state plasma concentrations of the parent drug RIS and its active metabolite, 9-hydroxy-risperidone (9-OH-RIS), were measured using specific liquid chromatography-tandem mass spectrometry assay. Psychopathology, side-effects of extrapyramidal symptoms (EPS) and CPT were also assessed. A negative correlation was found between CPT performance and the plasma RIS, 9-OH-RIS and its active moiety (RIS + 9-OH-RIS) concentrations. Both RIS and 9-OH-RIS have an impact on the CPT performance of schizophrenic patients. Optimal active moiety plasma concentration for best cognitive performance needs further study.

Adult↗
PubMed2004

The psychological well-being and associated factors of caregivers of outpatients with schizophrenia in Taiwan.

The purpose of this study attempted to understand the psychological well-being of caregivers of individuals with schizophrenia and factors affecting the caregivers' psychological well-being. More specifically, quality of life and psychiatric morbidity were used to represent the psychological well-being. Personal interviews using questionnaires were administrated to 57 caregivers. Data regarding knowledge of schizophrenia, perceived causes of schizophrenia, quality of life and psychiatric morbidity was collected. Psychiatrists assessed the symptoms severity of the schizophrenic patients. Compared with the controls, the psychological well-being of caregivers of patients with schizophrenia was poorer. There was a significant association between the positive symptoms score and the psychological well-being of caregivers. Life quality and psychiatric morbidity were affected by caregivers' knowledge of schizophrenia and beliefs about the cause of schizophrenia. Health care providers should consider the patients and their caregivers as a whole and provide psychoeducaiton to reduce the negative psychological impact of caregivers.

Adult↗
PubMed2004

Associated alterations of striatal dopamine D2/D3 receptor and transporter binding in drug-naive patients with schizophrenia: a dual-isotope SPECT study.

OBJECTIVE: In vivo imaging studies have revealed deregulated presynaptic or postsynaptic function of the midbrain dopaminergic system in patients with schizophrenia. To further delineate the neuropathological involvement of the presynaptic and postsynaptic dopamine neurons in schizophrenia, the authors examined brain D(2)-family receptor and dopamine transporter binding simultaneously in patients with drug-naive schizophrenia using the dual-isotope single photon emission computed tomography (SPECT) imaging technique. METHOD: Eleven patients with schizophrenia and 12 healthy comparison subjects were recruited. Striatal dopamine D(2)/D(3) receptor was measured with SPECT and [(123)I]iodobenzamide ([(123)I]IBZM), while dopamine transporter was measured with SPECT and [(99m)Tc]TRODAT-1. RESULTS: Striatal D(2)/D(3) receptor and dopamine transporter binding were unaltered in these drug-naive patients with schizophrenia. Nonetheless, D(2)/D(3) receptor binding measures were positively correlated with dopamine transporter binding measures in these patients but not in the comparison subjects. CONCLUSIONS: The associated presynaptic and postsynaptic disturbances of midbrain dopamine neurons could be clinically relevant in drug-naive patients with schizophrenia.

Adolescent↗
PubMed2003

Two case studies of hypothermia induced by an increased dosage of zotepine in a combination therapy.

The purpose of the present paper was to remind physicians that hypothermia is a possible side-effect of combining zotepine, valproate,and benzodiazepine. Two cases of hypothermia occurred after combining the use of zotepine, valproate, and benzodiazepine. The valproate was under therapeutic blood level when zotepine dosage was raised to 200 mg/day, and hypothermia occurred. The dosage of zotepine might constitute a positive correlation with hypothermia. The combination of zotepine, valproate or benzodiazepine may cause hypothermia as a side-effect.

Adult↗
PubMed2003

Correlation between performance on the Continuous Performance Test and economic costs in patients with schizophrenia.

The aim of the present study was to determine whether a relationship existed between the performance on the Continuous Performance Test (CPT) and the economic costs of schizophrenic patients in Taiwan. Forty-six schizophrenic patients and their caregivers were enrolled. The CPT is a vigilance task requiring the monitoring of rapid information processing and the detection of briefly presented target stimuli. Each patients undertook two CPT sections: the unmasked task and the masked task. Economic Cost Questionnaires were used for assessing the direct and indirect costs of the illness. The patients' performance on the masked version of the CPT correlated significantly with the indirect costs, although there was no significant relationship between CPT scores and direct costs. Schizophrenic patients with more severely impaired sustained attention, particularly as measured by CPT, may incur higher indirect costs.

Adolescent↗
PubMed2003

Olanzapine in Chinese treatment-resistant patients with schizophrenia: an open-label, prospective trial.

The role of olanzapine in treatment-resistant schizophrenia has still not been clearly resolved. In addressing this issue, the current report presents an open-label, prospective, 13 week trial with olanzapine use in Chinese schizophrenic patients who were resistant to more than two different classes of antipsychotics during a minimal 4 week treatment period for each antipsychotic drug at adequate dosage. Fifty-one inpatients were recruited after a cross-titration period and given 10-25 mg of olanzapine daily, without any concomitant antipsychotic medication. Patients were evaluated with the Brief Psychotic Rating Scale (BPRS), the Positive and Negative Symptoms Scale, the Clinical Global Impression Scale (CGI), the Abnormal Involuntary Movement Scale, the Simpson-Angus scale, and the Barnes Akathisia Scale. The olanzapine-treated patients showed significant improvement in both the positive and negative symptoms of schizophrenia by the end of the study. Overall, 20 of 51 (39.2%) responded to 10-25 mg of olanzapine per day as measured by the BPRS and CGI scores. Five patients dropped out due to the worsening of their psychotic symptoms, two patients discontinued owing to poor drug compliance, and the remaining patient complained of a lack of efficacy. Extrapyramidal side-effects were mild, and anticholinergic medications required has decreased. The present open study suggests that olanzapine may be effective and well-tolerated in Chinese treatment-resistant schizophrenic patients. Further double-blinded trials are needed to confirm this result.

Adult↗