[Kynurenine pathway in bipolar disorder].

Bipolar disorder (BD) is a chronic psychiatric illness which, among other things, is characterized by cerebral dysfunctions, cognitive disorders and sleep disturbances. The neurobiological basis of these processes remains unclear. In recent years, studies have focused on the role of immune-inflammatory mechanisms induced by the tryptophan metabolism pathway (TRP) and the kynurenine pathway (KYN). Emerging data correlates TRP and KYN metabolites with BD's pathophysiology and course. The purpose of this review is to search the available data on the involvement of KYN's pathway in the pathophysiology, the clinical presentation and the course of BD. A systematic literature review was conducted using web-based search engines provided by PubMed (for Medline database) and Google Scholar. The search languages were English and Greek and the entries Key phrases used for the research were: bipolar disorder, depression, mania, tryptophan, kynurenine pathway, cognitive dysfunction, sleep disorder, neuroimmunology, neuroinflammation manuscripts written or published in English and Greek language. The KYN pathway is actively involved in the pathophysiology of BD. The increase in neurotoxic weight of the neuroprotective derivatives of the pathway is associated with cognitive impairment that accompany the clinical presentation of the disease. In addition, some of these metabolites are also suspected of sleep disorders in BD. Further studies are needed to investigate the mechanisms involved. The KYN pathway is a highly interesting field of encounter and interaction of the immune inflammatory system with the CNS, both involved in the pathophysiology of BD in a variety of ways. Future research can focus on clarifying the role of the metabolites of this pathway, potentially highlighting new therapeutic goals. Additionally, consideration could be given to approaching the metabolites of the KYN pathway as biomarkers for early detection, staging and monitoring of BD patients.

Homocysteine, cortisol, diabetes mellitus, and psychopathology.

OBJECTIVE: This study investigates the association of homocysteine and cortisol with psychological factors in type 2 diabetic patients. METHOD: Homocysteine, cortisol, and psychological variables were analyzed from 131 diabetic patients. Psychological factors were assessed with the Eysenck Personality Questionnaire (EPQ), Hostility and Direction of Hostility Questionnaire (HDHQ), the Symptom Checklist 90-R (SCL 90-R), the Zung Self-Rating Depression Scale (ZDRS), and the Maudsley O-C Inventory Questionnaire (MOCI). Blood samples were taken by measuring homocysteine and cortisol in both subgroups during the initial phase of the study (T0). One year later (T1), the uncontrolled diabetic patients were reevaluated with the use of the same psychometric instruments and with an identical blood analysis. RESULTS: The relation of psychoticism and homocysteine is positive among controlled diabetic patients (P value = 0.006 < 0.05) and negative among uncontrolled ones (P value = 0.137). Higher values of cortisol correspond to lower scores on extraversion subscale (r(p) = -0.223, P value = 0.010). Controlled diabetic patients showed a statistically significant negative relationship between homocysteine and the act-out hostility subscale (r(sp) = -0.247, P = 0.023). There is a statistically significant relationship between homocysteine and somatization (r(sp) = -0.220, P = 0.043). CONCLUSIONS: These findings support the notion that homocysteine and cortisol are related to trait and state psychological factors in patients with diabetes mellitus type 2.

Oxytocin and diabetes mellitus: a strong biochemical relation. Review.

Oxytocin (OXT) is a neurohypophysial hormone which is synthesized in the paraventricular and supraoptic nuclei of the hypothalamus. OXT is currently attracting considerable attention because it has been discovered that it regulates various functions of behavior especially in the context of social interactions. OXT is a key component in bone formation, glycemia, male sexuality, cardiac differentiation and pregnancy and thus it is important to be further explored. The authors review various aspects of gestational diabetes, including definition, screening, diagnostic procedures, complications, clinical evaluation, indications of delivery and neonatal aspects. Not only the relation among diabetes mellitus, oxytocin and neurophysiology concerning erectile dysfunction, but also the role of OXT in the activity of arginine and vasopressin is investigated. It is imperative to develop technological and experimental methods that will be able to reveal the oxytocin and its potential.

Oxytocin and psychological factors affecting type 2 diabetes mellitus.

BACKGROUND: The aim of this study was to investigate the association of oxytocin with trait and state psychological factors in type 2 diabetic patients. METHODS: OXT and psychological variables were analyzed from 86 controlled diabetic patients (glycosylated haemoglobin A1c (HbA1c) < 7%) from 45 uncontrolled diabetic patients (HbA1c ≥ 7). Psychological characteristics were assessed with the Eysenck Personality Questionnaire (EPQ), while state psychological characteristics were measured with the Symptom Checklist 90-R (SCL 90-R). Blood samples were taken for measuring oxytocin in both subgroups during the initial phase of the study. One year later, the uncontrolled diabetic patients were reevaluated with the use of the same psychometric instruments. RESULTS: During the first evaluation of the uncontrolled diabetic patients, a statistically significant positive relationship between the levels of OXT and psychoticism in EPQ rating scale (P < 0.013) was observed. For controlled diabetic patients, a statistically significant negative relationship between oxytocin and somatization (P < 0.030), as well as obsessive-compulsive scores (P < 0.047) in SCL-90 rating scale, was observed. During the second assessment, the values of OXT decreased when the patients managed to control their metabolic profile. CONCLUSIONS: The OXT is in association with psychoticism, somatization, and obsessionality may be implicated in T2DM.

Possible epileptic origin of symptoms in a case exemplifying the sleeper kind of 'limbic psychotic trigger reaction'.

Limbic psychotic trigger reaction (LPTR) includes paroxysmal, motiveless, unplanned felonies, all committed during flat affect, autonomic arousal and a fleeting de novo psychosis. It is considered as a form of non-convulsive behavioural seizures (NCBS). A transient limbic hyperactivation is probably implicated that impairs prefrontal monitoring but preserves memory for the acts. LPTR may, however, not be limited to felonies which have attracted forensic attention. There may exist many more 'merely' social misbehaviours, undetected and untreated as a 'sleeper' case. This kind of possible undetected LPTR cases, exemplified by a patient who suffers from paroxysmal hallucinations triggering her to attempt to commit infanticide, is presented herein. Our patient had repetitive occurrence of episodes and remission of the symptomatology after the administration of oxcarbazepine, facts that support the epileptic origin of the disorder.

Design and implementation of an SVM-based computer classification system for discriminating depressive patients from healthy controls using the P600 component of ERP signals.

A computer-based classification system has been designed capable of distinguishing patients with depression from normal controls by event-related potential (ERP) signals using the P600 component. Clinical material comprised 25 patients with depression and an equal number of gender and aged-matched healthy controls. All subjects were evaluated by a computerized version of the digit span Wechsler test. EEG activity was recorded and digitized from 15 scalp electrodes (leads). Seventeen features related to the shape of the waveform were generated and were employed in the design of an optimum support vector machine (SVM) classifier at each lead. The outcomes of those SVM classifiers were selected by a majority-vote engine (MVE), which assigned each subject to either the normal or depressive classes. MVE classification accuracy was 94% when using all leads and 92% or 82% when using only the right or left scalp leads, respectively. These findings support the hypothesis that depression is associated with dysfunction of right hemisphere mechanisms mediating the processing of information that assigns a specific response to a specific stimulus, as those mechanisms are reflected by the P600 component of ERPs. Our method may aid the further understanding of the neurophysiology underlying depression, due to its potentiality to integrate theories of depression and psychophysiology.

Working memory deficits in multiple sclerosis: a controlled study with auditory P600 correlates.

BACKGROUND: Recently, the P600 component of event related potentials, a waveform that is conceived to be generated and/or modulated by basal ganglia and cingulate area has been considered an index of the completion of any synchronised operation after target detection, having much in common with working memory operation. Moreover, dysfunction of these brain structures as well as working memory deficits have been implicated in the pathophysiology of multiple sclerosis. The aim of this study was to investigate the patterns of P600 elicited during a working memory test in multiple sclerosis patients compared with healthy controls. METHODS: Twenty two definite, chronic progressive multiple sclerosis patients, with recent exacerbation of their illness, and 20 normal subjects matched for age, sex, and educational level, were studied with a computerised version of the digit span test of Wechsler batteries. Auditory P600 were measured during the anticipatory period of this test. RESULTS: The patient group, as compared with healthy controls, showed significantly reduced latencies of P600 at left frontal areas and reduced P600 amplitudes at left temporoparietal region. Moreover, memory performance of patients was significantly more impaired when compared with healthy controls. CONCLUSIONS: These findings may indicate that multiple sclerosis is associated with abnormal features of the completion of synchronised operation after target detection, as they are reflected by P600 amplitudes and latencies. Dysfunction of this mechanism may contribute to the identification of basic cognitive processes that could account for the cognitive deficits in multiple sclerosis.