The development of an ELISA for group IVA phospholipase A2 in human red blood cells.

An immunoassay for IVA phospholipase A2 in human red blood cells is described. The assay is a non-competitive sandwich assay in which increasing amounts of the measured protein produce increased luminescence. The antibodies used in the assay are directed against two unique epitopes of the molecule, which sequentially trap and detect the protein.

Breath ethane concentrations in healthy volunteers correlate with a systemic marker of lipid peroxidation but not with omega-3 Fatty Acid availability.

Ethane in human breath derives from lipid peroxidation, specifically the reaction between omega-3 fatty acids and reactive oxygen species. It has been proposed to be a non-invasive marker of oxidative stress, a deleterious process which may play an important role in the pathophysiology of several common diseases. It is unclear, however, whether ethane concentration actually correlates with systemic oxidative stress or whether it is primarily a marker of airway biochemistry.

Increased breath ethane levels in medicated patients with schizophrenia and bipolar disorder are unrelated to erythrocyte omega-3 fatty acid abundance.

Oxidative stress has been reported to be elevated in mental illness. Preliminary evidence suggests this phenomenon can be assessed non-invasively by determining breath levels of the omega-3 polyunsaturated fatty acid (PUFA) oxidation product ethane. This study compares alkane levels in chronic, medicated, patients with schizophrenia or bipolar disorder with those in healthy controls.

Antioxidant modulation of oxidant-stimulated uptake and release of arachidonic acid in eicosapentaenoic acid-supplemented human lymphoma U937 cells.

Omega-3 polyunsaturated fatty acids (PUFA) are increasingly finding use as treatments for a variety of medical conditions. PUFA supplementation can, however, result in increased oxidative stress causing elevated turnover rate of membrane phospholipids, impairment of membrane integrity and increased formation of inflammatory mediators. The aim of this study was to determine which antioxidant compounds were most effective in ameliorating the stimulation of phospholipid turnover by oxidative stress.

Differential effects of eicosapentaenoic and docosahexaenoic acids upon oxidant-stimulated release and uptake of arachidonic acid in human lymphoma U937 cells.

The use of n-3 polyunsaturated fatty acids, as found in fish-oil derived dietary supplements, as anti-inflammatory agents is supported by a variety of biochemical and physiological data. Recent studies investigating the therapeutic potential of long chain (>C20) n-3 fatty acids in mental illness have lead to the conclusion, however, that not all n-3 fatty acid types are equally efficacious. In particular eicosapentaeoic acid (EPA) appears to possess antidepressant and antipsychotic activity, while docosahexaenoic acid (DHA) does not, an effect suggested to be due to a differential ability to antagonize arachidonic acid (AA)-dependent cell signalling.

Delayed vasodilatory response to methylnicotinate in patients with unipolar depressive disorder.

Background: Recent evidence has suggested an important role for lipids in the etiology and treatment of depression. Methylnicotinate-induced vasodilation can be used to investigate lipid-dependent signalling mechanisms involving the phospholipase A2 (PLA2)/cyclooxygenase pathway, an important signalling system involved in the action of several neurotransmitters including serotonin. To investigate whether abnormalities in this signalling system may occur in depressive illness, we undertook a study of methylnicotinate response in unipolar depression (UD).

The investigation of cytosolic phospholipase A2 using ELISA.

Two studies of the behaviour of cytosolic phospholipase A(2) (cPLA(2)) in the red blood cell (RBC), as measured by ELISA, are described. In the first study we show a significant increase in cPLA(2) in patients with schizophrenia compared to controls and suggest that this measure, if corroborated, could be used as a diagnostic marker. In a second study we found that washing the RBC introduced an unknown confounding variable which led us to reject this study.

Increased levels of ethane, a non-invasive marker of n-3 fatty acid oxidation, in breath of children with attention deficit hyperactivity disorder.

Attention deficit hyperactivity disorder (ADHD) comprises a range of behavioural problems including inattention, hyperactivity and impulsivity. Diagnosis and treatment of the disorder is made difficult due to its unknown biological basis. Several studies have identified abnormalities in membrane fatty acids in some subjects with ADHD, and some success has been reported using lipid therapies.

Degradation of specific polyunsaturated fatty acids in red blood cells stored at -20 degrees C proceeds faster in patients with schizophrenia when compared with healthy controls.

Deficits in red blood cell (RBC) polyunsaturated fatty acids (PUFAs) have been extensively reported in schizophrenia although reports are inconsistent. A possible explanation for this inconsistency is varying storage conditions of blood samples prior to analysis, especially freezer storage temperature. We conducted a prospective investigation of fatty acid degradation rates in RBCs from healthy control subjects when samples from each individual were stored at both -20 degrees C or -70 degrees C.

On the relationship between methylnicotinate-induced skin flush and fatty acids levels in acute psychosis.

Vasodilation induced by methylnicotinate, a fatty acid- and cyclooxygenase-dependent process, is reduced or absent in patients with schizophrenia. This phenomenon has been suggested to be useful as a diagnostic test for the illness. To determine whether reduced flushing is specific to schizophrenia and is caused by a deficiency in membrane fatty acids, the extent of topically applied methylnicotinate-induced vasodilation was measured in 23 subjects with schizophrenia, 20 subjects with bipolar disorder and 34 healthy volunteers along with red cell fatty acid concentrations and measures of clinical severity.