Differences in potential biomarkers of delirium between acutely ill medical and elective cardiac surgery patients.

Background/aims: The pathophysiology of delirium is poorly understood. Increasing evidence suggests that different pathways might be involved in the pathophysiology depending on the population studied. The aim of the present study was to investigate potential differences in mean plasma levels of neopterin, amino acids, amino acid ratios and homovanillic acid between two groups of patients with delirium.

Cycloid psychoses in the psychosis spectrum: evidence for biochemical differences with schizophrenia.

Cycloid psychoses (CP) differ from schizophrenia regarding symptom profile, course, and prognosis and over many decades they were thought to be a separate entity within the psychosis spectrum. As to schizophrenia, research into the pathophysiology has focused on dopamine, brain-derived neurotrophic factor, and glutamate signaling in which, concerning the latter, the N-methyl-d-aspartate receptor plays a crucial role. The present study aims to determine whether CP can biochemically be delineated from schizophrenia.

Increased CSF levels of aromatic amino acids in hip fracture patients with delirium suggests higher monoaminergic activity.

Background: To examine whether delirium in hip fracture patients was associated with changes in the levels of amino acids and/or monoamine metabolites in cerebrospinal fluid (CSF) and serum.

Methods: In this prospective cohort study, 77 patients admitted with an acute hip fracture to Oslo University Hospital, Norway, were studied. The concentrations of amino acids in CSF and serum were determined by high performance liquid chromatography.

Cerebrospinal fluid levels of neopterin are elevated in delirium after hip fracture.

Background: The inflammatory cell product neopterin is elevated in serum before and during delirium. This suggests a role for disordered cell-mediated immunity or oxidative stress. Cerebrospinal fluid (CSF) neopterin levels reflect brain neopterin levels more closely than serum levels.

Potential Influence of Aspirin on Neopterin and Tryptophan Levels in Patients with a Delirium.

In an study, it was found that aspirin might decrease neopterin production and tryptophan degradation. The aim of the present study was to evaluate the possible association between aspirin use and mean neopterin and tryptophan levels in patients with and without a delirium and whether the use of aspirin is associated with a decreased prevalence of delirium. Neopterin and tryptophan levels were determined previously in acutely ill admitted patients aged ≥65 years.

Disturbed Serotonergic Neurotransmission and Oxidative Stress in Elderly Patients with Delirium.

Background: Oxidative stress and disturbances in serotonergic and dopaminergic neurotransmission may play a role in the pathophysiology of delirium.

Aims: In this study, we investigated levels of amino acids, amino acid ratios and levels of homovanillic acid (HVA) as indicators for oxidative stress and disturbances in neurotransmission.

Methods: Plasma levels of amino acids, amino acid ratios and HVA were determined in acutely ill patients aged ≥65 years admitted to the wards of Internal Medicine and Geriatrics of the Erasmus University Medical Center and the ward of Geriatrics of the Havenziekenhuis, Rotterdam, The Netherlands.

Relationship between plasma homovanillic acid and outcome in patients with psychosis spectrum disorders.

Background: Psychosis spectrum disorders, especially schizophrenia, have been linked to disturbed dopaminergic activity in the brain. Plasma homovanillic acid (pHVA) levels partly represent dopaminergic metabolism in the central nervous system. In the present study associations between (changes in) pHVA levels, symptom severity and symptomatic improvement in patients with psychoses were investigated.

The tryptophan kynurenine pathway, neopterin and IL-6 during vulvectomy and abdominal hysterectomy.

Background: Surgery has wide ranging immunomodulatory properties of which the mechanism is poorly understood. In order to investigate how different types of surgery influence inflammation, we designed a longitudinal observational study investigating two inflammatory profiles of two separate patient groups undergoing gynaecological operations of differing severity. In addition to measuring the well known inflammatory markers neopterin and IL-6, we also determined the kynurenine/tryptophan ratio.

Neopterin: a potential biomarker for delirium in elderly patients.

Background/aims: The diagnosis of delirium is not supported by specific biomarkers. In a previous study, high neopterin levels were found in patients with a postoperative delirium. In the present study, we investigated levels of neopterin, interleukin-6 (IL-6) and insulin-like growth factor-1 (IGF-1) in acutely ill admitted elderly patients with and without a delirium.

Acute serotonin depletion releases motivated inhibition of response vigour.

Rationale: The neurotransmitter serotonin has long been implicated in the motivational control of behaviour. Recent theories propose that the role of serotonin can be understood in terms of an interaction between a motivational and a behavioural activation axis. Experimental support for these ideas, however, has been mixed.

Tryptophan depletion in chronic fatigue syndrome, a pilot cross-over study.

Background: Chronic fatigue syndrome (CFS) is still an enigmatic disorder. CFS can be regarded as a complex disorder with tremendous impact on lives of CFS-patients. Full recovery without treatment is rare.

BDNF and S100B in psychotic disorders: evidence for an association with treatment responsiveness.

Objective: Brain-derived neurotrophic factor (BDNF) and S100B are involved in brain plasticity processes and their serum levels have been demonstrated to be altered in patients with psychoses. This study aimed to identify subgroups of patients with psychotic disorders across diagnostic boundaries that show a specific symptom profile or response to treatment with antipsychotics, by measuring serum levels of BDNF and S100B.

Methods: The study sample consisted of 58 patients with DSM-IV psychotic disorders.

Effect of major and minor surgery on plasma levels of arginine, citrulline, nitric oxide metabolites, and ornithine in humans.

Objective: To determine the effect of surgical invasiveness on plasma levels of arginine, citrulline, ornithine, and nitric oxide (NO) in humans.

Background: Surgical trauma may have a profound effect on the metabolism of NO. However, human studies reported both increased and decreased NO levels after hemorrhagic shock.

Potential neuroprotective effects of oxyresveratrol against traumatic injury.

Oxyresveratrol is a potent antioxidant and free-radical scavenger found in mulberry wood (Morus alba L.) with demonstrated protective effects against cerebral ischemia. We analyzed the neuroprotective ability of oxyresveratrol using an in vitro model of stretch-induced trauma in co-cultures of neurons and glia, or by exposing cultures to high levels of glutamate.

The tryptophan depletion theory in delirium: not confirmed in elderly hip fracture patients.

Background: The tryptophan depletion theory assumes that low tryptophan levels are present in delirium. These lower levels may be regarded as a biochemical marker for cellular immune activation, which may lead to increased catabolism of tryptophan into kynurenine via stimulation of the enzyme indoleamine 2,3-dioxygenase (IDO) by interferon-γ.

Objective: To compare plasma tryptophan and kynurenine levels, and IDO activity in hospitalized patients with and without delirium.

Psychiatric side effects and fluctuations in serotonergic parameters in the treatment of chronic hepatitis C infection.

Introduction: Treatment of hepatitis C with peginterferon induces psychiatric side effects. These might include changes in serotonergic function.

Methods: Twenty-two hepatitis C patients were treated with peginterferon.

High preoperative plasma neopterin predicts delirium after cardiac surgery in older adults.

Objectives: To examine the association between plasma levels of pterins and amino acids and postoperative delirium.

Design: Prospective cohort study.

Setting: Cardiothoracic service in an university hospital in Rotterdam, the Netherlands.

Serum brain-derived neurotrophic factor level in relation to illness severity and episode duration in patients with major depression.

Background: Since there are few data on the possible association between BDNF levels and characteristics of major depression, the present study assesses brain-derived neurotrophic factor (BDNF) levels in three drug-free patient samples, and explores whether episode duration, and severity correlate with serum BDNF levels.

Method: Serum BDNF levels were measured in 42 drug-free patients with major depression. The duration of the index episode and the presence of psychotic features were assessed with the Schedule for Affective Disorders and Schizophrenia, and the severity of depression was measured with the 17-item Hamilton Rating Scale for Depression.

Automated analysis of primary amino acids in plasma by high-performance liquid chromatography.

The concentration of primary amino acids (AAs) in plasma can accurately be determined using high-performance liquid chromatography (HPLC). Before the analysis can be performed, several steps have to be regarded. First, the time and method of blood withdrawal, type of blood tube, use of medication, and differences in dietary intake are important factors that should be standardized.

Mast cell degranulation mediates bronchoconstriction via serotonin and not via renin release.

To verify the recently proposed concept that mast cell-derived renin facilitates angiotensin II-induced bronchoconstriction bronchial rings from male Sprague-Dawley rats were mounted in Mulvany myographs, and exposed to the mast cell degranulator compound 48/80 (300 microg/ml), angiotensin I, angiotensin II, bradykinin or serotonin (5-hydroxytryptamine, 5-HT), in the absence or presence of the renin inhibitor aliskiren (10 micromol/l), the ACE inhibitor captopril (10 micromol/l), the angiotensin II type 1 (AT1) receptor blocker irbesartan (1 micromol/l), the mast cell stabilizer cromolyn (0.3 mmol/l), the 5-HT2A/2C receptor antagonist ketanserin (0.1 micromol/l) or the alpha1-adrenoceptor antagonist phentolamine (1 micromol/l).

Tryptophan depletion affects the autonomic stress response in generalized social anxiety disorder.

In generalized social anxiety disorder (gSAD), serotonergic dysfunctions are found, as well as abnormalities of the autonomic nervous system (ANS) in basal conditions and of the hypothalamic pituitary adrenal (HPA) axis in response to psychological challenges. These findings raise the question whether these phenomena are interrelated. Therefore we designed a study in which two groups with nine pair wise age and gender matched gSAD patients (total of 10 men and 8 women), who were successfully treated with a selective serotonin reuptake inhibitor (SSRI), underwent a tryptophan depletion challenge (TD) or a placebo condition.

Plasma levels of nitric oxide related amino acids in demented subjects with Down syndrome are related to neopterin concentrations.

Subjects with Down syndrome (DS) have abnormalities in virtually all aspects of the immune system and almost all will be affected with Alzheimer's disease (AD). It is thought that nitric oxide (NO) is involved in the pathophysiology of AD. In the present study, including a total of 401 elderly DS subjects, the spectrum of plasma amino acids and neopterin was investigated and related to development of AD.

Neopterin and the risk of dementia in persons with Down syndrome.

Persons with Down syndrome show an altered immune response and an increased susceptibility to Alzheimer's disease. In a prospective study, we examined whether the plasma neopterin level, a marker for cell-mediated immune activation and inflammation, is associated with an increased risk of dementia in persons with Down syndrome. Plasma concentrations of neopterin were determined in a population-based study of 394 persons with Down syndrome, who were screened annually for dementia.

Nitric oxide production and monoamine oxidase activity in cancer patients during interferon-alpha therapy.

Both increased and decreased nitric oxide (NO) synthesis have been reported in patients treated with interferon-alpha (IFN-alpha). Animal studies showed that IFN-alpha administration results in increased levels of biogenic amines, subsequent activation of monoamine oxidases (MAOs), and finally in a change in NO production due to the H(2)O(2) generated by MAOs. We examined the potential relationship between NO production in plasma and MAO-B activity in platelets of 43 cancer patients during 8 weeks of treatment with IFN-alpha.