Biomedical subjects

Hara Tsekou

Publications and source records attributed to Hara Tsekou.

4 recordsLinked to original sources

PubMed2006

Effect of schizotypy on cognitive performance and its tuning by COMT val158 met genotype variations in a large population of young men.

BACKGROUND: Mirroring schizophrenia, specific dimensions of schizotypy are related to cognitive dysfunction. The relation of schizotypy and state psychopathology to cognitive performance and its link to catechol-O-methyltransferase (COMT) val(158) met genotype variations was studied in a large sample of young men. METHODS: State psychopathology and schizotypy were assessed with self-rated questionnaires. Cognitive performance was assessed with tests of reasoning ability, sustained attention, and verbal and spatial working memory. Subjects were genotyped for the val(158) met polymorphism of the gene for COMT (low enzymatic activity met/met, intermediate met/val, and high val/val). RESULTS: The val/val group had higher scores in measures of state psychopathology as well as negative and disorganized schizotypy dimensions, whereas there was no effect of COMT genotype on cognitive performance measures. Structural equation modeling showed that cognitive performance accuracy but not speed decreased with increasing negative schizotypy, increased with increasing paranoid schizotypy, and was not affected by state psychopathology. Increasing val loading resulted in a dose-dependent increase in the factor loading for the relation between negative schizotypy and cognitive performance accuracy. CONCLUSIONS: Different schizotypal phenotypes had opposing relations to cognitive performance in the population. COMT genotype modulated the relation between the negative schizotypal phenotype and cognitive performance.

Adolescent↗

PubMed2006

The mirror antisaccade task: direction-amplitude interaction and spatial accuracy characteristics.

In this study we examined the performance of human subjects in three oculomotor tasks: a visually guided saccade task (VST), a simple antisaccade task (SAT) and a mirror antisaccade task (MAT). The stimulus presentation was identical for all three tasks, and the differentiation of the tasks was based on the instruction given to the subjects. Subjects were instructed to either look at a visually presented target location (visually triggered saccade task), or to look at the opposite direction of the visually presented target (simple antisaccade task) or finally to look at the mirror location opposite to the location of the visually presented target (mirror antisaccade task). The loading of the simple antisaccade task with the addition of the amplitude requirement did not affect the percentage of directional errors but slowed down the onset of antisaccade execution by 19 ms. The amplitude of the directionally correct antisaccade in the mirror antisaccade task showed a significant distortion of the true mirror target location. This dysmetria followed the same qualitative pattern to that observed for the visually guided saccades, i.e., a near-target hypermetria together with a far-target hypometria, but both these features were exaggerated in the mirror antisaccade task. This distorted amplitude modulation of mirror antisaccade amplitude was completely lost in corrected antisaccades that followed a directional error.

Brain↗

PubMed2006

Short-term psychological impact on family members of intensive care unit patients.

OBJECTIVE: This study aimed to evaluate the short-term psychological impact on family members of intensive care unit (ICU) patients during their stay in the unit. METHODS: Thirty-two first-degree relatives of patients treated in the ICU of two general hospitals were investigated for symptoms of early posttraumatic stress reaction, anxiety, and depression. Patients' and relatives' sociodemographic data and information pertaining to the patients' ICU treatment were collected. Family members were assessed at intake and before discharge through the Center for Epidemiological Studies Depression Scale, the State-Trait Anxiety Inventory, and the Impact of Event Scale. RESULTS: High rates of anxiety, depressive (97%), and posttraumatic stress (81%) symptoms were recorded at the initial assessment. Although symptoms remitted significantly, 87% and 59% of the sample fulfilled the criteria for a depressive and posttraumatic stress reaction, respectively, at the second assessment. Women exhibited higher levels of distress and more persisting symptoms than men did. Trait anxiety was the most significant predictor (P<.001) of the severity of depressive symptoms and the single predictor of the development of posttraumatic stress reaction (P<.000); also, state anxiety was a predictor of the development of posttraumatic stress symptoms, especially of the female gender. CONCLUSIONS: Family members of ICU patients exhibit high levels of distress that persist throughout their relatives' hospitalization. Women and individuals with high trait anxiety are at increased risk for developing such reactions. Severe early anxiety responses predicted the development of posttraumatic stress symptoms. Early case identification and intervention may prevent the full development of posttraumatic stress disorder.

Adjustment Disorders↗

PubMed2006

Melatonin secretion after head injury: a pilot study.

PRIMARY OBJECTIVE: To investigate the circadian rhythm of serum melatonin in patients with traumatic brain injury (TBI) during Intensive Care Unit (ICU) stay and its relationship with core body temperature fluctuations and measures of severity of their condition. METHODS AND PROCEDURES: The pilot study was conducted in the ICU of a general hospital in Athens, Greece. Blood melatonin was determined in eight patients consecutively admitted at the ICU following severe head injury, eight times per day during the first and second day following admission. Core body temperature was recorded at hourly intervals. Patients were also assessed with the Glasgow Coma Score (GCS) and the APACHE II score. RESULTS: Melatonin concentrations were lower than the normally reported values. Mean night-time melatonin levels were higher than mean daytime levels both on the first and second days, although not statistically significant. Diurnal variation of melatonin was associated with the GCS. Thus, patients with low GCS (n = 4) did not exhibit a consistent diurnal variation of melatonin, whereas those with high GCS (n = 4) retained the normally expected fluctuations. CONCLUSIONS: ICU-treated TBI patients exhibit reduced melatonin levels and a circadian secretion profile which is related to the severity of the injury. Patients with more severe head trauma exhibit a clearly disrupted pattern of melatonin secretion, whereas those with less severe trauma preserve a relatively intact diurnal rhythm. Furthermore, the diurnal secretion pattern of melatonin appeared to be dissociated from the circadian rhythm of core body temperature. These preliminary findings may have implications for the management of TBI patients.

Adult↗