Siu Wa Tang

Influence of exercise on serum brain-derived neurotrophic factor concentrations in healthy human subjects.

The effect of short-term exercise (15 min step-exercise) on serum brain-derived neurotrophic factor (BDNF) levels was evaluated in healthy human subjects. Results showed a short-term, significant increase in serum BDNF levels after exercise. Intra-individual differences in serum BDNF levels were remarkably small on the rest day and also when compared to rest values on the day of the exercise test. Inter-individual differences, on the other hand, were larger by comparison. The result of this study supports the need for larger sample size in studies on BDNF changes in psychiatric disorders or psychiatric drug effects.

The Japanese version of the Barratt Impulsiveness Scale, 11th version (BIS-11) : Its reliability and validity

Abstract No instrument for assessing impulsiveness has been developed in Japan. After translating the Barratt Impulsiveness Scale 11th version (BIS‐11) into Japanese, we investigated reliability and validity in student (n = 34) and worker (n = 416) samples. To assess test–retest reliability, the intraclass coefficient between test and retest was calculated in the student sample. Internal consistency was examined by calculating Cronbachs alpha in the worker sample. To see factor validity, we examined by confirmatory factor analysis whether the three‐factor model, proposed by a previous report, fit the data. The results showed that the Japanese version of the BIS‐11 had excellent test–retest reliability and acceptable internal consistency reliability. In addition, the Japanese version was judged to have similar factor structure to the original one. The Japanese version of the BIS‐11 is a reliable and valid measure and has possible utility for assessing impulsiveness.

Paroxetine shifts imipramine metabolism

The combination of selective serotonin reuptake inhibitors with tricyclic antidepressants has proven useful in treatment-resistant depression but has the potential for adverse drug-drug interactions. In the present study, the metabolism of a single dose of imipramine was studied before and after treatment with paroxetine. Paroxetine induced significant elevations of approximately 50% in half-life, area under the curve, and Cmax of imipramine and decreased clearance twofold. The effects on desipramine pharmacokinetics were even more pronounced. These findings indicate a significant interaction of paroxetine with the CYP2D6 isoenzyme.

Misinterpretation of facial expression: A cross‐cultural study

Accurately recognizing facial emotional expressions is important in psychiatrist‐versus‐patient interactions. This might be difficult when the physician and patients are from different cultures. More than two decades of research on facial expressions have documented the universality of the emotions of anger, contempt, disgust, fear, happiness, sadness, and surprise. In contrast, some research data supported the concept that there are significant cultural differences in the judgment of emotion. In this pilot study, the recognition of emotional facial expressions in 123 Japanese subjects was evaluated using the Japanese and Caucasian Facial Expression of Emotion (JACFEE) photos. The results indicated that Japanese subjects experienced difficulties in recognizing some emotional facial expressions and misunderstood others as depicted by the posers, when compared to previous studies using American subjects. Interestingly, the sex and cultural background of the poser did not appear to influence the accuracy of recognition. The data suggest that in this young Japanese sample, judgment of certain emotional facial expressions was significantly different from the Americans. Further exploration in this area is warranted due to its importance in cross‐cultural clinician–patient interactions.

Reduced haloperidol/haloperidol ratios in plasma: Polymorphism in Japanese psychiatric patients

We measured plasma concentrations of haloperidol (HAL) and its metabolite, reduced haloperidol (RHAL), by high performance liquid chromatography (HPLC) in 45 Japanese psychiatric patients receiving HAL. Plasma levels of HAL had a highly positive correlation with daily dose per body weight. Plasma RHAL/HAL ratios had also a dose-dependent relationship, but their distribution was nonnormal and a bimodal pattern with an antimode at 0.7 was apparent by probit analysis. There were 8 subjects (18%) with high RHAL/HAL ratios (mean = 1.26, SD = 0.41) and 37 subjects (82%) with low RHAL/HAL ratios (mean = 0.42, SD = 0.13). RHAL/HAL ratios showed little intraindividual variability (+/- 10.6%), while interindividual variability was large. This may suggest that pharmacogenetic factors are involved in the metabolism of HAL and RHAL.

Effect of venlafaxine on imipramine metabolism.

The present study was designed to determine the effect of venlafaxine on imipramine metabolism in an attempt to elucidate the potential for cytochrome P450 drug-drug interactions with venlafaxine. We examined the metabolism of a single 100-mg dose of imipramine before and after treatment with venlafaxine, 50 mg three times a day. Eight male subjects were phenotyped for CYP2D6 activity. Two subjects were poor metabolizers of dextromethophan, and data from the remaining six subjects (mean age=45.3+/-15) were analyzed. Venlafaxine increased imipramine C(max) and elevated AUC by 40%. Desipramine clearance and volume of distribution were reduced by 20% and 25%, respectively. These findings are consistent with a statistically significant, but clinically modest impact of venlafaxine on CYP2D6-metabolized substrates.

Tyrosine kinase inhibitors regulate serotonin uptake in platelets

Uptake of tritiated serotonin into human platelets was found to be rapidly inhibited by the tyrosine kinase inhibitors, genistein and methyl 2,5-dihydroxycinnamate. Binding studies indicated that uptake inhibition did not correlate with direct binding of these inhibitors to the transporter. Chelation of mobilizable intracellular Ca2+ did not inhibit the effects of genistein on uptake. These results suggest a more direct, non-Ca2+ mediated effect of tyrosine kinase inhibitors on uptake.

Cultural difference in recognition of facial emotional expression: Contrast between Japanese and American raters

Using the Japanese and Caucasian Facial Expressions of Emotion (JACFEE) photo set, the relationship between recognition and intensity ratings of universal facial expressions of emotions in 123 Japanese undergraduate students was examined and compared with data reported by American raters. In Japanese raters, although the intensity was rated as high for some of the poses, their correctness scores were poor, suggesting a serious misjudgment of the intended emotions as defined in the JACFEE photo set. Only in Japanese raters were significant relationships between the intensity scores and the percentage correctness scores for sadness detected (r = 0.97, P < 0.0001), but no significant relationship was observed for other emotions. The robust correlation suggests the possibility that Japanese raters might be more responsive to certain emotional expressions when they are fully or intensely expressed. It is proposed that the facial emotional expression paradigm cannot be applied to the psychiatric setting without first refining for cultural differences.

Brain σ receptors labelled by [3H]nemonapride

Binding of [3H]nemonapride and [3H]raclopride was examined in the brain areas of three species (rat, cow and human). The results indicated that [3H]nemonapride binding is inhibited by selective sigma receptor ligands in frontal cortex, striatum and cerebellum. Only the striatum showed significant dopaminergic sites as defined by sulpiride. Use of the subtraction method of [3H]nemonapride minus [3H]raclopride binding as a measure of D4 dopamine receptor binding may, therefore, also include a sigma receptor component.

Factor analysis of the EMBU scale in a large sample of Japanese volunteers.

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