Biomedical subjects

D Helmeste

Publications and source records attributed to D Helmeste.

12 recordsLinked to original sources

PubMed2001

Differential judgement of static facial expressions of emotions in three cultures.

Judging facial expressions of emotions has important clinical value in the assessment of psychiatric patients. Judging facial emotional expressions in foreign patients however, is not always easy. Controversy has existed in previous reports on cultural differences in identifying static facial expressions of emotions. While it has been argued that emotional expressions on the face are universally recognized, experimental data obtained were not necessarily totally supportive. Using the data reported in the literature, our previous pilot study showed that the Japanese interpreted many emotional expressions differently from USA viewers of the same emotions. In order to explore such discrepancies further, we conducted the same experiments on Chinese subjects residing in Beijing. The data showed that, similar to the Japanese viewers, Chinese viewers also judged many static facial emotional expressions differently from USA viewers. The combined results of the Chinese and the Japanese experiments suggest a major cross-cultural difference between American and Asian viewers in identifying some static facial emotional expressions, particularly when the posed emotion has negative connotations. The results have important implications for cross-cultural communications when facial emotional expressions are presented as static images.

Adult↗

PubMed2000

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.

Adult↗

PubMed2000

Digital psychiatry.

The American managed care movement has been viewed as a big experiment and is being watched closely by the rest of the world. In the meanwhile, computer-based information technology (IT) is changing the practice of medicine, much more rapidly than managed care. A New World of digitized knowledge and information has been created. Although literature on IT in psychiatry is largely absent in peer-reviewed psychiatric journals, IT is finding its way into all aspects of medicine, particularly psychiatry. Telepsychiatry programs are becoming very popular. At the same time, medical information sites are flourishing and evolving into a new health-care industry. Patient-physician information asymmetry is decreasing as patients are gaining easy access to medical information hitherto only available to professionals. Thus, psychiatry is facing another paradigm shift, at a time when most attention has been focused on managed care. In this new digital world, knowledge and information are no longer the sole property of professionals. Value will migrate from traditional in-person office-based therapy to digital clinical products, from in-person library search and classroom didactic instruction to interactive on-line searches and distance learning. In this time of value migration, psychiatrists have to determine what their 'distinctive competence' is and where best to add value in the health-care delivery value chain. The authors assess the impact of IT on clinical psychiatry and review how clinical practice, education and research in psychiatry are expected to change in this emerging digital world.

Communication↗

PubMed1999

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.

Adolescent↗

PubMed1999

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.

Adult↗

PubMed1997

Rapid determination of venlafaxine and O-desmethylvenlafaxine in human plasma by high-performance liquid chromatography with fluorimetric detection.

A rapid and sensitive high-performance liquid chromatographic technique for simultaneous measurement of plasma venlafaxine (VEN) and its active metabolite O-desmethylvenlafaxine (ODV) is described. The process begins with the extraction of VEN and ODV, with maprotiline (MAP) as internal standard, from human plasma into an intermediate organic mixture of hexane-isoamyl alcohol and finally into an aqueous solution of 0.05% phosphoric acid. Isocratic separation of VEN, ODV and MAP is carried out by utilizing a reversed-phase butyl-bonded column (C4/E) with mobile phase consisting of acetonitrile and 40 mM phosphate buffer, pH 6.8 (50:50, v/v). Detection of VEN, ODV and MAP is done by mean of fluorimetry with excitation and emission wavelengths set at 276 and 598 nm, respectively. As low as 1.0 ng/ml VEN is detectable; while the limit of detection for ODV is 5 ng/ml. C.V. (%) of intra-day samples for both VEN and ODV are less than 10% at three concentrations tested (10.0, 50.0, 100.0 ng/ml). Similarly, over the same nominal concentrations, the precision of inter-day (5 days) samples also results in C.V. (%) smaller than 10% for both compounds, except for ODV measured at 10 ng/ml (C.V.<15%). Approximately, 100% VEN can be extracted from plasma; whereas, for ODV the recovery rate is nearly 70%. This present method is rapid, sensitive, accurate and simple for routine clinical monitoring of plasma VEN and its major metabolite ODV.

Antidepressive Agents, Second-Generation↗

PubMed1996

Brain sigma 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.

Animals↗

PubMed1996

Serotonin indices and impulsivity in normal volunteers.

Hormonal responses to oral paroxetine were examined in a group of healthy subjects. The calcium response to serotonin (5-hydroxytryptamine, 5HT), mediated by platelet 5HT2A, was also measured. Paroxetine elicited a cortisol response that was directly correlated with the magnitude of platelet calcium response. The cortisol response was also correlated with the trait of impulsivity. These results suggest that paroxetine may be a useful probe in studies of serotonergic systems.

Administration, Oral↗

PubMed1996

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.

Adult↗

PubMed1995

Serotonin-stimulated intracellular calcium mobilization in platelets from alcoholic men.

Numerous lines of evidence have suggested a key role for serotonin (5-hydroxytryptamine, 5HT) pathways in the regulation of alcohol consumption. To explore the functioning of the 5HT2 receptor in alcoholism, 5HT-stimulated intracellular calcium response was measured in platelets from abstinent alcoholic patients and normal comparison subjects. No difference in resting or stimulated calcium levels was observed. This finding suggests that 5HT2 receptor function is unaffected in non-drinking alcoholic subjects. The previously reported 5HT inhibition in actively drinking alcoholic subjects is likely to be a state rather than trait marker of alcoholism.

Adult↗

PubMed1990

Anti-imipramine antibodies recognize endogenous serotonin uptake and imipramine binding inhibitors.

Calf brain and human platelet extracts purified by Bio-Gel P2 column chromatography contained substances that inhibited serotonin uptake and 3H-imipramine binding. Some of these endogenous substances were also recognized by rabbit antibodies produced against imipramine. The data suggest the possible existence of endogenous serotonin uptake modulators, which may possess a partial molecular structure similar to that identified by the antibodies.

Animals↗

PubMed1988

Amplified gene for the epidermal growth factor receptor in a human glioblastoma cell line encodes an enzymatically inactive protein.

The gene encoding the receptor for epidermal growth factor was amplified two- to fivefold in the human glioblastoma cell line SF268. The amplified gene gave rise to abundant quantities of receptor that bound EGF with a high affinity (Kd, 0.35 nM). The binding of ligand failed to elicit cellular DNA synthesis, however, and the receptor was enzymatically inactive. We presume that the amplified receptor gene carries a mutation(s) that affects several aspects of the receptor's function. Characterization of the mutation(s) may illuminate how structure dictates function in the receptor protein.

Cell Cycle↗