Evaluation of CSF 8-iso-prostaglandin F2α and erythrocyte anisocytosis as prognostic biomarkers for delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage.

Delayed cerebral ischemia (DCI) is a serious, life-threatening, complication affecting patients who have survived the initial bleeding from a ruptured intracranial aneurysm. Due to the challenging diagnosis, potential DCI prognostic markers should be of value in clinical practice. According to recent reports isoprostanes and red blood cell distribution (RDW) showed to be promising in this respect. We conducted a prospective study of 27 aSAH patients and control group (n = 8). All patients from the study group were treated within the first day of the initial bleeding. We collected data regarding clinical status and results of biochemical, and radiological examinations. We measured cerebrospinal fluid (CSF) concentration of 8-iso-prostaglandin F2α (F2-IsoP) and RDW on days 1, 3, and 5. Both CSF F2-IsoP level and RDW-SD measured on day 1 were significant predictors of DCI. The receiver operating characteristics curve for DCI prediction based on the multivariate model yielded an area under the curve of 0.924 (95% CI 0.824-1.000, p < 0.001). In our study, the model based on the combination of RDW and the level of isoprostanes in CSF on the first day after the initial bleeding showed a prognostic value for DCI prediction. Further studies are required to validate this observation.

Increased plasma 8,12-iso-iPF2alpha- VI levels in relapsing multiple sclerosis patients are not predictive of disease progression.

BACKGROUND: Oxidative stress plays an important role in multiple sclerosis (MS). Isoprostanes are biomarkers for oxidative stress and have been related to neurological disease progression. OBJECTIVE: To study whether plasma isoprostane levels were related to disease progression in MS. METHODS: Plasma levels of 8,12-iso-iPF2alpha-VI were determined in 17 patients with clinically isolated syndrome (CIS), 41 relapsing-remitting MS (RRMS) patients and 5 primary progressive MS (PPMS) patients and related to MRI and clinical disease parameters. RESULTS: Isoprostane levels were similar in CIS (60.9, interquartile range (IQR): 47.7-77.7 pg/ml) and RRMS patients (65.3, IQR: 51.9-82.8 pg/ml). The plasma levels were lower in PPMS patients (42.5, IQR: 37.1-49.9) pg/ml, p<0.05) compared to CIS and RRMS patients in this cohort, which was not confirmed in a second cohort. Baseline isoprostane levels were not related to clinical progression defined by conversion form CIS to RRMS or change in Expanded Disability Status Scale (EDSS) or MS Functional Composite (MSFC) scores during six years of follow-up (CIS + RRMS), nor to change in volume of gadolinium enhancing lesions, T2 lesion load or T1 hypointense lesion load during 2.8 years of follow-up (CIS + RRMS). CONCLUSION: These results do not support a strong role of 8,12-iso-iPF2alpha-VI in the prediction of disease progression in MS.

Plasma platelet-activating factor-acetyl hydrolase activity and the levels of free forms of biomarker of lipid peroxidation in cerebrospinal fluid of patients with aneurysmal subarachnoid hemorrhage.

BACKGROUND: Free radicals and lipid peroxidation are thought to be related to the vasospasm generation after subarachnoid hemorrhage (SAH). Plasma platelet-activating factor-acetyl hydrolase (PAF-AH) degrades phospholipids with an oxidatively modified fatty acyl chain. OBJECTIVE: To compare plasma PAF-AH activity and free forms of biomarker of lipid peroxidation in cerebrospinal fluid (CSF) between patients with and without symptomatic vasospasm (SVS) after SAH. METHODS: The identification of PAF-AH in CSF was performed by Western blotting. The genotype at position 279 of the plasma PAF-AH gene was determined. The activities of PAF-AH and the levels of free 8-iso-prostaglandin F2α (free isoPs), free hydroxyoctadecadienoic acid (free HODE), and free hydroxyeicosatetraenoic acid (free HETE) in CSF were measured. RESULTS: The PAF-AH in CSF was confirmed to be only the plasma type. The genotype of the plasma PAF-AH was not different between patients with and without SVS. Free isoPs, free HODE, and free HETE showed higher values in patients without SVS in 0 to 4 days and 5 to 9 days after SAH. The PAF-AH activity also was higher in patients without SVS in 0 to 4 days and 5 to 9 days after SAH. The associations between PAF-AH activity and free isoPs, and between PAF-AH activity and free HODE were significant. CONCLUSION: Oxidized lipids of lipoproteins and blood cell membranes produced by reactive oxygen species in CSF when SAH occurs may be the main source of lipid peroxidation. Plasma PAF-AH can hydrolyze oxidized phospholipids, and may attenuate the spreading of lipid peroxidation and participate in defense mechanisms against vasospasm after SAH.

Simultaneous HPLC-MS-MS quantification of 8-iso-PGF(2alpha) and 8,12-iso-iPF(2alpha) in CSF and brain tissue samples with on-line cleanup.

Quantitation of isoprostanes such as 8-iso-PGF(2alpha) and 8,12-iso-iPF(2alpha)-VI in biological fluids has been proposed as a reliable test of oxidant stress and inflammation in a variety of disorders. This paper presents a liquid chromatography method with tandem mass spectrometry detection for the simultaneous analysis of these two isoprostanes in human CSF and brain tissue samples. An API 5000 triple quadrupole instrument (AB Sciex, Foster City, CA, USA) with an APCI ion source was used in this study. Aliquots of CSF samples (0.25mL) were treated with a methanol:zinc sulfate mixture followed by on-line cleanup on an extraction column (Validated-C(18)) with 0.1% formic acid. The brain tissue samples were homogenized and lipids were extracted using Folch solution. Solid-phase extraction columns (C(18)) were used for the purification of the brain isoprostane fraction. Chromatographic separation was achieved using an analytical column (Synergi C(18) HydroRP) with 0.1% formic acid in water and a mixture of methanol:acetonitrile under isocratic conditions. The mass spectrometer was operated in the MRM scan and negative ion mode. The quadrupoles were set to detect the molecular ions [M-H](-) and high mass fragments of isoprostanes: m/z 353-->193amu (8-iso-PGF(2alpha)) and m/z 353-->115amu (8,12-iso-iPF(2alpha)-VI) and their deuterated internal standards: m/z 357-->197amu (8-iso-PGF(2alpha)-d(4)) and m/z 364-->115amu (8,12-iso-iPF(2alpha)-VI-d(11)). The lower limit of quantification was 2.5pg/mL for 8-iso-PGF(2alpha) and 5.0pg/mL for 8,12-iso-PF(2alpha)-VI for the CSF method and 10.0pg/0.1g of tissue and 30.0pg/0.1g of tissue for 8-iso-PGF(2alpha) and 8,12-iso-iPF(2alpha)-VI, respectively, for the brain tissue method. No ion suppression or enhancement of the detection of 8-isoPGF(2alpha), 8,12-isoPF(2alpha)-VI or both internal standards was found.

Cerebrospinal fluid oxidative stress during chemotherapy of acute lymphoblastic leukemia in children.

In this study the authors addressed the question whether neurotoxicity due to the chemotherapy of acute lymphoblastic leukemia (ALL) is associated with cerebrospinal fluid (CSF) oxidative stress. Examination of 38 ALL patients revealed significant increases in 8-isoprostane concentration and important decreases in total antioxidative capacity of CSF during therapy. The mean 8-isoprostane level at diagnosis was 9.05 +/- 1.62 pg/mL, and no correlations with initial leukocytosis, organomegaly, and lactate dehydrogenase levels were noted. 8-Isoprostane concentrations were increased on the 59th day of treatment (mean level: 24.85 +/- 7.59 pg/mL [P < .01]) and remained elevated at 4 points of the consolidation phase (17.28 +/- 2.16 pg/mL [P < .05]; 22.72 +/- 6.04 pg/mL [P < .05]; 24.92 +/- 6.31 pg/mL [P < .01]; 32.32 +/- 7.94 pg/mL [P < .01]) as compared to their level at diagnosis. The mean total antioxidative capacity at diagnosis was 203.08 +/- 6.17 mumol/L and was remarkably decreased on the 59th day of treatment (189.76 +/- 1.9 mumol/L [P < .05]) and at one point of the consolidation phase (188.29 +/- 3.46 mumol/L [P < .05]) as compared to the level at diagnosis. This study indicates that neurotoxicity of standard ALL treatment may be related to oxidative stress.

Kinetic change of oxidative stress in cerebrospinal fluid of mice infected with Angiostrongylus cantonensis.

The cerebrospinal fluid (CSF) of C57BL/6 mice infected with Angiostrongylus cantonensis was examined for kinetic changes in oxidative stress parameters, including reactive oxygen species (ROS), superoxide dismutase (SOD), catalase, malondialdehyde (MDA), 8-isoprostane, and 8-hydroxy-2'-deoxyguanosine (8-OHdG). The ROS increased gradually in the early stage of infection. During days 12-30 post-infection, the infected mice revealed ROS levels significantly higher than that in uninfected controls (P < 0.001). The ROS levels peaked at day 24 and then returned to that observed in uninfected controls at day 45 post-infection. The kinetics of MDA, 8-isoprostane, and 8-OHdG concentration changes observed in the CSF of the infected mice corresponded with kinetic changes in ROS levels. Thus, the excess ROS caused lipid peroxidation and DNA damage to cells in the central nervous system (CNS) of mice infected with A. cantonensis despite the increased antioxidant SOD and catalase enzyme activities during post-infection days 12-30. The oxidative stress in the CNS of C57BL/6 mice was apparently increased by diseases associated with A. cantonensis infection.

The longitudinal profile of CSF markers during external lumbar drainage.

BACKGROUND: External lumbar drainage (ELD) is known as a good predictor of favourable outcome in shunting patients suffering from idiopathic normal pressure hydrocephalus (iNPH). METHODS: Eleven patients suffering from iNPH had a lumbar drain (LD) inserted for 72 h and participated in a research study to quantify any improvement in their clinical symptoms. The lumbar cerebrospinal fluid (CSF) levels of lactate, 8-isoprostane, vascular endothelial growth factor (VEGF), glial fibrillar acidic protein (GFAP), neurofilament (heavy chain) protein (NF (h)), Abeta(1-42) (beta-amyloid) and total tau were assayed samples from all three time points. RESULTS: The concentrations of lactate, VEGF, GFAP and tau increased significantly during the 72 h of drainage. There were also increases in 8-isoprostane and Abeta(1-42) (non significant). The concentration of NF (h) was reduced significantly following 72 h of drainage. There was a significant positive correlation between Abeta(1-42) and total tau in the first sample. GFAP was negatively correlated in a significant fashion with both Abeta(1-42) and total tau. NF (h) was negatively correlated with VEGF. CONCLUSION: Evidence is provided that ELD is producing measurable changes in the CSF composition of patients with iNPH. The present paper discusses how such changes may be implicated in the pathophysiology of the condition.

The effects of normal aging and ApoE genotype on the levels of CSF biomarkers for Alzheimer's disease.

While cerebrospinal fluid (CSF) biomarkers are of use in the prediction and diagnosis of Alzheimer's disease our understanding of the background effects of age and the ApoE genotype is limited. Seventy-eight community-based normal volunteers (mean age 60+/-10 years, range 36-86) were examined to determine the relationships between CSF measures of total tau (T-tau), hyperphosphorylated tau (P-tau 231), amyloid beta (Abeta42/Abeta40 ratio), and isoprostane (IP) with age and ApoE genotype. The results showed that age by epsilon4 genotype interactions were found for P-tau231 (beta=1.82; p<0.05) and IP (beta=1.6; p<0.05). T-tau CSF concentration increased with age. The increasing CSF concentrations of P-tau and IP in epsilon4 carriers suggest that early tauopathy and oxidative stress may be related to the increased risk for AD. The data also suggest that T-tau changes are more age dependent than Abeta changes. The evidence that P-tau231 and IP are the earliest markers for the neuronal damage related to AD awaits longitudinal study.

Carbon monoxide-prostaglandin E2 interaction in the hypothalamic circulation.

The heme oxygenase (HO)-carbon monoxide pathway was earlier shown to increase hypothalamic blood flow after inhibition of nitric oxide synthesis in rats. We hypothesized that this effect is mediated by prostaglandin E2 (PGE2). Inhibition of constitutive HO activity decreased cerebral PGE2 production and simultaneously increased hypothalamic nitric oxide synthase (NOS) activity without changing hypothalamic blood flow. Furthermore, HO blockade induced cyclooxygenase-dependent decrease and NOS-mediated increase of the hypothalamic blood flow after inhibition of NOS and cyclooxygenase, respectively. Therefore, constitutive carbon monoxide release seems to have two indirect effects on the hypothalamic circulation: vasodilation mediated by PGE2 and vasoconstriction as a result of NOS inhibition.

Nimesulide-induced antipyresis in rats involves both cyclooxygenase-dependent and independent mechanisms.

This study evaluates the antipyretic activity of nimesulide, a cyclooxygenase (COX-2) selective inhibitor in rats. The effects of nimesulide on lipopolysaccharide (LPS)-induced cerebrospinal prostaglandin E(2) (PGE(2)) and prostaglandin F(2alpha) (PGF(2alpha)) and on plasma tumor necrosis factor-alpha (TNF-alpha) levels were also evaluated. Male Wistar rats received an i.p. injection of LPS, or i.c.v. injections of interleukin-1beta (IL-1beta), interleukin-6 (IL-6), TNF-alpha, macrophage inflammatory protein-1alpha (MIP-1alpha), arachidonic acid, PGE(2), PGF(2alpha), corticotrophin-releasing factor (CRF) or endothelin-1 (ET-1). Nimesulide or indomethacin administered i.p 30 min prior LPS, IL-1beta, IL-6, TNF-alpha or arachidonic acid reduced the febrile response and PGE(2) or PGF(2alpha) levels in LPS-febrile rats but did not modify PGE(2)-induced fever. Nimesulide, but not indomethacin, reduced the fever induced by MIP-1alpha, PGF(2alpha), CRF or ET-1. Plasma TNF-alpha levels in LPS-treated rats were also reduced by nimesulide. These findings confirm that the antipyretic effect of nimesulide differs from the antipyretic scenario with the non-selective cyclooxygenase blocker indomethacin. Additional mechanisms, including inhibition of increased plasma TNF-alpha, may contribute to its antipyretic activity in rats.

A non-enzymatic derived arachidonyl peroxide, 8-iso-prostaglandin F2 alpha, in cerebrospinal fluid of patients with aneurysmal subarachnoid hemorrhage participates in the pathogenesis of delayed cerebral vasospasm.

We performed serial measurements of 8-iso-prostaglandin F2alpha (8-iso-PGF2alpha), a non-enzymatic derived arachidonyl peroxide, in the cerebrospinal fluid (CSF) of 34 patients with subarachnoid hemorrhage (SAH). Patients were treated with open or endovascular surgery within 48 h of onset. Delayed cerebral vasospasm was verified by the presence of a low-density area on CT scan indicating focal cerebral infarction occurring after symptomatic delayed vasospasm. Concentrations of 8-iso-PGF2alpha in the CSF of 15 patients exhibiting delayed cerebral vasospasm were compared with those of 19 patients who did not exhibit vasospasm. The concentrations of 8-iso-PGF2alpha in the CSF of patients showing vasospasm were 42.4+/-37.1 pg/ml (mean+/-S.D., n=12) on Days 0-2, 66.4+/-41.0 pg/ml (n=14) on Days 3-5, 118.5+/-89.9 pg/ml (n=15) on Days 6-8, 86.2+/-70.2 pg/ml (n=11) on Days 9-11, 48.8+/-31.8 pg/ml (n=10) on Days 12-14, 27.8+/-20.1 pg/ml (n=7) after Day 20, while the concentrations in patients not showing vasospasm were 24.8+/-12.0 pg/ml (n=18) on Days 0-2, 25.7+/-15.2 pg/ml (n=19) on Days 3-5, 47.5+/-52.3 pg/ml (n=18) on Days 6-8, 56.7+/-72.0 pg/ml (n=13) on Days 9-11, 34.2+/-53.1 pg/ml (n=15) on Days 12-14, 20.1+/-18.2 pg/ml (n=10) after Day 20. CSF concentrations of 8-iso-PGF2alpha on Days 3-5 and Days 6-8 were significantly higher in patients showing vasospasm as compared to patients not showing vasospasm. CSF levels of 8-iso-PGF2alpha in patients showing vasospasm gradually increased in the days after onset of SAH and peaked on Days 6-8. Levels returned to normal after Day 20. These values on Days 3-5, Days 6-8, and Days 9-11 were significantly higher than the value after Day 20. Considering these data and the biological activities of 8-iso-PGF2alpha, such as development of inflammation, membrane perturbation and vasoconstriction, we conclude that 8-iso-PGF2alpha may play a role in delayed cerebral vasospasm after SAH.

The effects of selective and nonselective cyclooxygenase inhibitors on endothelin-1-induced fever in rats.

It was previously shown that sustained fever can be induced in rats by central injection of endothelin-1 (ET-1). This peptide appears to participate in the mechanism(s) of LPS-induced fever, which is reduced by pretreatments with ET(B) receptor antagonists. In this study, we compared the effects of a nonselective cyclooxygenase (COX) inhibitor, indomethacin, with those of two selective COX-2 inhibitors, celecoxib and lumiracoxib, on ET-1-induced fever in rats. Fever induced in conscious animals by ET-1 (1 pmol icv) or LPS (5 mug/kg iv) was prevented by pretreatments with celecoxib (5 and 10 mg/kg) or lumiracoxib (5 mg/kg) given by oral gavage 1 h before stimuli. Lower doses of celecoxib had partial (2.5 mg/kg) or no effect (1 mg/kg). Indomethacin (2 mg/kg ip) partially inhibited fever induced by LPS but had no effect on ET-1-induced fever. The levels of PGE(2) and PGF(2alpha) in the cerebrospinal fluid (CSF) of pentobarbital sodium-anesthetized rats were significantly increased 3 h after the injection of LPS or ET-1. The latter increase was abolished by celecoxib at all tested doses and by indomethacin. In conclusion, selective COX-2 inhibitors were able to prevent ET-1-induced fever, indicating a role for COX-2 in this phenomenon. However, the fact that reduced CSF PG levels obtained with indomethacin and a low dose of celecoxib are not accompanied by changes in fever induced by ET-1, along with the lack of inhibitory effects of indomethacin on ET-1 fever, suggests that the latter might also involve COX-2-independent mechanisms.

Cerebrospinal fluid isoprostanes are not related to inflammatory activity in relapsing-remitting multiple sclerosis.

Oxidative stress leads to lipid peroxidation and may contribute to the pathogenesis of lesions in multiple sclerosis (MS), an autoimmune disease characterised by inflammatory as well as degenerative phenomena. We previously found that cerebrospinal fluid (CSF) levels of isoprostane 8-epi-PGF2alpha, a marker of free radical damage and lipid peroxidation in vivo, were elevated in MS patients. Such levels were correlated with the degree of disability and reduced in subjects under steroid therapy. Here we investigated weather the CSF isoprostane levels correlated with disease inflammatory activity. To this aim, we enrolled 41 relapsing-remitting (RR) MS patients who underwent at the same time full neurological examination, NMR-imaging brain scan and diagnostic CSF test. No evidence of correlation was found between 8-epi-PGF2alpha levels and the presence of gadolinium (Gd)-enhancing NMR lesions or the time elapsed since the last relapse. We suggest that isoprostanes are not useful as surrogate inflammatory markers in MS. However, they may represent a sensitive index of degenerative phenomena, which can persist also in the absence of inflammatory activity.

Increased CSF levels of prostaglandin E(2) in variant Creutzfeldt-Jakob disease.

The concentration of the cyclooxygenase product prostaglandin E(2) was sixfold higher in CSF samples from 18 cases of variant Creutzfeldt-Jakob disease (CJD) than in a group of eight subjects with other noninflammatory neurologic diseases, and comparable to those found in a group of six patients affected by diseases with a known inflammatory component. This finding suggests that cyclooxygenase activity may have a role in variant CJD pathogenesis, as previously reported in sporadic CJD.

In vivo neutralization of endogenous brain fractalkine increases hippocampal TNFalpha and 8-isoprostane production induced by intracerebroventricular injection of LPS.

Fractalkine is a chemokine widely and constitutively expressed in the brain and, as suggested by in vitro studies, it is involved in brain inflammatory responses. In this study, we have investigated the in vivo anti-inflammatory potential of fractalkine in a model of neuroinflammation induced by intracerebroventricular injection of lipopolysaccharide (LPS) in rats. LPS induces a rapid and acute production of the pro-inflammatory cytokine, TNFalpha, in hippocampus and cerebrospinal fluid (CSF), and an increase of 8-isoprostane levels, a marker of oxidative stress, in hippocampus. Although intracerebroventricular injection of fractalkine has no effect on TNFalpha and 8-isoprostane production, neutralization of endogenous fractalkine within the brain with a specific anti-fractalkine antibody potentiates LPS effects. These data emphasize the involvement of constitutive brain fractalkine in the control of inflammatory reaction in CNS.

Cerebrospinal fluid abeta42, tau, and f2-isoprostane concentrations in patients with Alzheimer disease, other dementias, and in age-matched controls.

OBJECTIVE: To test the hypothesis that quantification of cerebrospinal fluid (CSF) F(2)-isoprostanes (F(2)-IsoPs), in vivo biomarkers of free radical damage, along with CSF Abeta(42) and tau levels improves laboratory diagnostic accuracy for Alzheimer disease (AD). PARTICIPANTS: Patients with probable AD (n = 19), dementias other than AD (n = 8), and age-matched controls (n = 10). MAIN OUTCOME MEASURES: Cerebrospinal fluid concentrations of Abeta(42) and tau were determined by a commercially available test (Athena Diagnostics, Worcester, Mass). Cerebrospinal fluid F(2)-IsoP levels were quantified by gas chromatography/mass spectrometry. RESULTS: Individuals were classified as AD or non-AD by a published method using CSF Abeta(42) and tau levels (95% sensitivity, 50% specificity), by CSF F(2)-IsoP levels greater than 25 pg/mL and Abeta(42) concentrations less than 1125 pg/mL (90% sensitivity, 83% specificity), and by combined analysis using CSF F(2)-IsoP, Abeta(42), and tau levels (84% sensitivity, 89% specificity). CONCLUSION: Cerebrospinal fluid F(2)-IsoP quantification may enhance the accuracy of the laboratory diagnosis of AD.

Gonadotropin-releasing hormone in third ventricular cerebrospinal fluid of the heifer during the estrous cycle.

The release profile of GnRH in cerebrospinal fluid (CSF) and its correlation with LH in peripheral blood of ovary-intact heifers during the estrous cycle were investigated. A silicon catheter was placed into the third ventricle of six heifers using ultrasonography. During the mid-luteal phase, the heifers were injected with prostaglandin F(2alpha) to induce luteolysis. Surges of CSF GnRH (66.7 h after prostaglandin F(2alpha) administration) and peripheral LH (66.3 h) occurred simultaneously and were coincident with the onset of estrus (67.0 h). Duration of elevated GnRH concentration considerably overlapped with the estrous phase in each of the heifers. Mean pulse frequencies of both GnRH and LH were significantly higher during the proestrous and early luteal phases than during the mid-luteal phase, while mean concentration and pulse amplitude of both GnRH and LH were not different between these three phases. Of all the GnRH pulses identified, more than 80% were accompanied by an LH pulse during the proestrous and early luteal phases. However, the proportion of GnRH pulses that were coincident with an LH pulse during the mid-luteal phase decreased to 60%. The results clearly demonstrate that a dynamic (pulse) and longer-term (surge) changes of GnRH release into CSF are physiologically expressed during the estrous cycle in heifers, and the pattern of pulsatile GnRH secretion in heifers depends upon their estrous cycle.

Isoprostanes, novel markers of oxidative injury, help understanding the pathogenesis of neurodegenerative diseases.

Isoprostanes are prostaglandin-like compounds which are formed by free radical catalysed peroxidation of arachidonic acid esterified in membrane phospholipids. They are emerging as a new class of sensitive, specific and reliable markers of in vivo lipid peroxidation and oxidative damage. Since their initial description of in 1990, the rapid development of analytical methods for isoprostane measurement has allowed to overcome some of the pitfalls of the previous and most widely used methods of assessing free radical injury. Here, we summarise the current knowledge on these novel class lipid peroxidation products and the advantages of monitoring their formation to better define the involvement of oxidative stress in neurological diseases. Although the literature data are still not abundant, they indicate that in vivo or post mortem cerebrospinal fluid and brain tissue levels of isoprostane are increased in some diseases such as multiple sclerosis, Alzheimer's disease, Huntington's disease, and Creutzfeldt-Jakob disease.

Cerebrospinal fluid isoprostane shows oxidative stress in patients with multiple sclerosis.

The CSF level of the isoprostane 8-epi-prostaglandin (PG)-F2alpha (a reliable marker of oxidative stress in vivo) was three times higher in subjects with definite MS than in a benchmark group of subjects with other neurologic diseases. This increase was not correlated with that of PGE2 levels, measured as an index of cyclooxygenase activity, and was much lower in steroid-treated patients. The levels of 8-epi-PGF2alpha were moderately correlated with the degree of disability.

The magnitude of brain lipid peroxidation correlates with the extent of degeneration but not with density of neuritic plaques or neurofibrillary tangles or with APOE genotype in Alzheimer's disease patients.

Numerous post mortem studies have demonstrated increased accumulation of lipid peroxidation products in diseased regions of Alzheimer's disease (AD) brain; however, few have used techniques that quantify the magnitude of lipid peroxidation in vivo. F(2)-isoprostanes (F(2)-IsoP's) are exclusive products of free radical-mediated peroxidation of arachidonic acid, and their quantification has been widely used as an in vivo biomarker of the magnitude of lipid peroxidation. We have determined F(2)-IsoP concentrations in lateral ventricular fluid (VF) from 23 AD and 12 age-matched controls and correlated these with neuropathological and genetic markers of AD. VF F(2)-IsoP levels were significantly elevated in AD patients compared with controls (p < 0.01) and were significantly correlated with three different measures of brain degeneration: reduction in brain weight (p < 0.01), degree of cortical atrophy (p < 0.01), and Braak stage (p = 0.02). When analysis was restricted to AD patients only, VF F(2)-IsoP levels still were significantly correlated to reduction in brain weight and degree of cortical atrophy (p < 0.05). VF F(2)-IsoP concentrations were not related to density of neuritic plaques or neurofibrillary tangles in seven brain regions, or to the number of epsilon4 alleles of the apolipoprotein E gene (APOE). These data suggest that the magnitude of brain lipid peroxidation is closely related to the extent of brain degeneration in AD but is not significantly influenced by the density of neuritic plaques or neurofibrillary tangles, or the number of epsilon4 alleles of APOE.