Lipid peroxidation in the pathogenesis of neuroborreliosis.

This study analyzed the onset of lipid peroxidation (LPO) in neuroborreliosis and the effects of ceftriaxone therapy on LPO. Twenty-two patients with early neuroborreliosis and 22 healthy subjects were studied. LPO in the cerebrospinal fluid (CSF), as well as the plasma and urine was estimated by the levels of reactive aldehydes: 4-hydroxynonenal (4-HNE), 4-hydroxyhexenal, malondialdehyde, and 4-oxononenal, F2-isoprostanes and A4/J4-neuroprostanes (NPs). The plasma level of 4-HNE-protein adducts arachidonic acid (AA), docosahexaenoic acid (DHA) and vitamin E was determined. Additionally, enzymatic activities of phospholipase A2 (PLA2), platelet-activating factor acetylhydrolase (PAF-AH) and glutathione peroxidase (GSH-Px) were determined. A decrease of AA, DHA levels and GSH-Px activity in plasma was associated with a significant increase of aldehydes in the CSF, plasma and urine. Similarly, the increase of F2-isoprostanes and NPs in the CSF and plasma was associated with the decreased activity of PLA2 and PAF-AH. Ceftriaxone therapy cured patients and reduced the levels of F2-isoprostanes, NPs and reactive aldehydes. However, the activities of PLA2 and PAF-AH increased. Pathophysiological association of neuroborreliosis with systemic LPO was revealed. Effective antibiotic therapy attenuated LPO. Biomarkers of LPO could be useful to monitor the onset of neuroborreliosis and show the effectiveness of pharmacotherapy.

Associative and predictive biomarkers of dementia in HIV-1-infected patients.

BACKGROUND: Infection with HIV can result in a debilitating CNS disorder known as HIV dementia (HIV-D). Since the advent of highly active antiretroviral therapy (HAART), the incidence of HIV-D has declined, but the prevalence continues to increase. In this new era of HIV-D, traditional biomarkers such as CSF viral load and monocyte chemotactic protein 1 levels are less likely to be associated with dementia in patients on HAART and biomarkers that can predict HIV-D have not yet been identified. OBJECTIVE: To identify biomarkers that are associated with and can predict HIV-D. METHODS: We grouped patients with HIV based on changes in cognitive status over a 1-year period and analyzed sphingolipid, sterol, triglyceride, antioxidant, and lipid peroxidation levels in CSF. RESULTS: We found that increased levels of the vitamin E and triglyceride C52 predicted the onset or worsening of dementia. Elevated levels of sphingomyelin were associated with inactive dementia. Elevated levels of ceramide and the accumulation of 4-hydroxynonenals were associated with active dementia. CONCLUSIONS: We interpret these findings to indicate that early in the pathogenesis of HIV dementia, there is an up-regulation of endogenous antioxidant defenses in brain. The failure of this attempted neuroprotective mechanism leads to the accumulation of sphingomyelin and moderate cognitive dysfunction. The breakdown of this enlarged pool of sphingomyelin to ceramide and the accumulation of highly reactive aldehydes are associated with declining cognitive function. Thus, elevations in endogenous protective mechanisms may identify patients who are at increased risk of the development of HIV dementia.

Antioxidant capacity and protein oxidation in cerebrospinal fluid of amyotrophic lateral sclerosis.

BACKGROUND: The causes of Amyotrophic Lateral Sclerosis (ALS) are unknown. A bulk of evidence supports the hypothesis that oxidative stress and mitochondrial dysfunction can be implicated in ALS pathogenesis. METHODS =: We assessed, in cerebrospinal fluid (CSF) and in plasma of 49 ALS patients and 8 controls, the amount of oxidized proteins (AOPP, advanced oxidation protein products), the total antioxidant capacity (FRA, the ferric reducing ability), and, in CSF, two oxidation products, the 4-hydroxynonenal and the sum of nitrites plus nitrates. RESULTS: The FRA was decreased (p = 0.003) in CSF, and AOPP were increased in both CSF (p = 0.0039) and plasma (p = 0.001) of ALS patients. The content of AOPP was differently represented in CSF of ALS clinical subsets, resulting in increase in the common and pseudopolyneuropathic forms (p < 0.001) and nearly undetectable in the bulbar form, as in controls. The sum of nitrites plus nitrates and 4-hydroxynonenal were unchanged in ALS patients compared with controls. CONCLUSION: Our results, while confirming the occurrence of oxidative stress in ALS, indicate how its effects can be stratified and therefore implicated differently in the pathogenesis of different clinical forms of ALS.

Treatment from birth of nonketotic hyperglycinemia due to a novel GLDC mutation.

OBJECTIVE: To determine whether the devastating outcome of neonatal-onset glycine encephalopathy (NKH) could be improved by instituting treatment immediately at birth rather than after symptoms are already well established. METHODS: A newborn with NKH diagnosed prenatally following the neonatal death of a previous affected sibling was treated from birth with oral sodium benzoate (250 mg/kg/day) and the NMDA receptor antagonist ketamine (15 mg/kg/day) immediately after sampling cord blood and cerebrospinal fluid (CSF) for glycine determination. Glycine cleavage system (CGS) activity was determined in placental tissue. Mutation analysis was performed by sequencing all GLDC, GCSH and AMT exons. RESULTS: CSF glycine (99 micromol/L, reference 3.8-8.0) was already markedly elevated at birth. GCS activity in placental tissue was severely reduced (2.6% of controls). A novel homozygous GLDC c.482A-->G(Y161C) missense mutation was identified. Neonatal hypotonia and apnea did not occur but the long-term outcome was poor, with intractable seizures and severe psychomotor retardation. This contrasts with the favorable outcome with early treatment in variant NKH with mild GCS deficiency (Ann Neuol 2004;56:139-143). INTERPRETATION: Prospective treatment with this regimen can favorably modify the early neonatal course of severe NKH but does not prevent the poor long-term outcome, suggesting glycine-induced prenatal injury and/or ongoing postnatal damage.

Aging and oxidative stress in progressive supranuclear palsy.

Progressive supranuclear palsy (PSP) is a neurodegenerative disorder, which may possibly be induced by oxidative stress. However, the age-related alteration of the endogenous antioxidant system is not well understood. To better understand this, we measured Cu/Zn-superoxide dismutase (SOD), glutathione peroxidase (GPx), and 4-hydroxynonenal (HNE)-conjugated GPx in cerebrospinal fluid of PSP patients by enzyme linked immunosorbent assay. A significant increase in the Cu/Zn-SOD level was detected in PSP group compared with controls. The levels of Cu/Zn-SOD and GPx in PSP group showed positive correlations with age. Two-thirds of total GPx was present as the HNE-conjugated form with positive correlation in PSP group. In conclusion, the endogenous antioxidant system of PSP patients appears to be activated with aging, however, it might be unable to function effectively because of conjugation with HNE.

Increased lipid peroxidation in sera of ALS patients: a potential biomarker of disease burden.

BACKGROUND: Markers of oxidative stress and immune activation are significantly elevated in postmortem ALS CNS tissue, although the relevance to pathogenesis is unclear. OBJECTIVE: To determine the degree and distribution of oxidative stress and immune activation in living ALS patients and whether these levels correlate with the rate of progression or extent of disease. METHOD: Serum and CSF samples from sporadic ALS (sALS) patients were assayed for 4-hydroxy-2,3-nonenal (HNE), a lipid peroxidation product, and monocyte chemoattractant protein-1alpha (MCP-1alpha), a beta-chemokine, by high-performance liquid chromatography and ELISA and compared with levels measured in disease and normal control subjects by one-way analysis of variance. SALS serum levels were analyzed in relation to rate of progression, stage of disease, and drug therapy. RESULTS: HNE levels were significantly elevated in the sera and spinal fluid of sALS patients compared with control populations and positively correlated with extent of disease but not rate of progression. MCP-1alpha levels were also elevated in the sera of sALS patients, with the exception of the neurodegenerative disease control subjects, but decreased with advancing disease. CSF MCP-1alpha levels were not different between the sampled populations. There was no correlation between serum HNE and MCP-1alpha levels in sALS patients and extent of disease. However, an inverse relationship between HNE and MCP-1alpha was demonstrable in vitro. Low levels of HNE stimulated release of MCP-1alpha from cultured human macrophages, whereas high levels inhibited release of MCP-1alpha. CONCLUSIONS: These data confirm the presence of increased oxidative stress and immune activation in ALS patients. HNE is also suggested as a possible biomarker of disease.

The effect of increased concentrations of homocysteine on the concentration of (E)-4-hydroxy-2-nonenal in the plasma and cerebrospinal fluid of patients with Alzheimer's disease.

There is evidence that increased blood concentrations of homocysteine may be a risk factor for Alzheimer's disease. (E)-4-hydroxy-2-nonenal (HNE) is a neurotoxic product of lipid peroxidation that is increased in the ventricular fluid and brains of patients with Alzheimer's disease. We measured the concentrations of homocysteine, HNE, vitamin B(12) and folate in the plasma of 27 patients with Alzheimer's disease and 25 control subjects. There was a statistically significant increase in the plasma concentration of homocysteine (P < 0.001) and HNE (P < 0.001) in the Alzheimer's disease patients compared to the control group. There was a significant decrease in the plasma concentration of vitamin B(12) (P < 0.001) and folate (P = 0.002) in the Alzheimer's group compared to the controls. There was a significant positive correlation between the plasma concentrations of homocysteine and HNE in the patients with Alzheimer's disease (r = 0.661, P < 0.001). A significant negative correlation was found between the plasma concentration of homocysteine and the plasma concentrations of vitamin B(12) (r = -0.605, P = 0.0006) and folate (r = 0.586, P = 0.001). We also measured the concentrations of homocysteine, HNE, vitamin B(12) and folate in the cerebrospinal fluid (CSF) of 8 patients with Alzheimer's disease compared to 6 control subjects. The concentrations of homocysteine (P = 0.032) and HNE (P = 0.001) were significantly higher in the CSF of Alzheimer's patients than in the control subjects. There were significant positive correlations between the CSF concentrations of homocysteine and HNE (r = 0.924, P = 0.001). There was also a significant positive correlation between the plasma concentration of homocysteine and the CSF concentrations of homocysteine (r = 0.850, P = 0.007) and HNE (r = 0.092, P = 0.002). These results demonstrate that there is a relationship between increased homocysteine concentrations and increased HNE concentrations in Alzheimer's disease.

Superoxide production by primary rat cerebral endothelial cells in response to pneumococci.

Animal studies of experimental bacterial meningitis have provided evidence for an involvement of reactive oxygen species (ROS) in the pathophysiology of this disease. Using a lucigenin-enhanced chemiluminescence (CL) method, we tested whether primary rat cerebral endothelial cells can be induced to release ROS upon stimulation with pneumococci. In addition, we determined CSF levels of two markers of lipid peroxidation in patients with bacterial meningitis, compared to patients with viral meningitis and noninflammatory neurological disorders. Malondialdehyde/4-hydroxynonenal concentrations were significantly elevated in CSF samples obtained from patients with bacterial meningitis (23.12+/-5.47 microM), as compared to both control groups (5.43+/-0.18 microM and 7.80+/-0.33 microM, respectively). Cerebromicrovascular endothelial cells, granulocytes, and the macrophage cell line RAW 264.7 (but not astrocytes and neuron-like cells) produced an increase in CL intensity after stimulation with pneumococci. The peak value produced by endothelial cells (500+/-83 cpm) was significantly lower than the maximum CL response in macrophages (1386+/-142 cpm; p<0.05). After addition of superoxide dismutase (SOD), the CL signal returned to baseline values. Equal to the CL technique, nitroblue tetrazolium (NBT) staining of RAW 264.7 showed SOD-inhibitable formazan precipitation when stimulated with pneumococci. In conclusion, this study suggests an important role of endothelial cells in the pathophysiology of bacterial meningitis-namely as a source for ROS production.

Presence of 4-hydroxynonenal in cerebrospinal fluid of patients with sporadic amyotrophic lateral sclerosis.

A marker of lipid peroxidation 4-hydroxynonenal (HNE) was elevated in the cerebrospinal fluid (CSF) of a patient with sporadic amyotrophic lateral sclerosis (sALS) compared with that of most patients with other neurological diseases. Such elevations of HNE were sufficient to kill cyclic adenosine monophosphate (cAMP)-differentiated motor neuron hybrid cells in vitro, and anti-oxidants prevented this HNE-dependent cell death. These data suggest that oxidative stress and lipid peroxidation are associated with and may promote motor neuron degeneration in sALS.

Determination of the lipid peroxidation product (E)-4-hydroxy-2-nonenal in clinical samples by gas chromatography--negative-ion chemical ionisation mass spectrometry of the O-pentafluorobenzyl oxime.

(E)-4-Hydroxy-2-nonenal (HNE) is a highly reactive product of the free radical-stimulated lipid peroxidation of phospholipid-bound arachidonic acid in cellular membranes. We describe a sensitive and specific method for the determination of HNE in clinical samples. The method is based on the formation of the O-pentafluorobenzyl (O-PFB) oxime derivative of HNE, which is then extracted and cleaned up by solid-phase extraction. The HNE O-PFB oxime is then analysed without further derivatisation by capillary column gas chromatography-negative ion chemical ionisation mass spectrometry (GC-NICI-MS) using selected-ion monitoring. Concentrations down to the pmol range were achieved using deuterated HNE as an internal standard. The method was used to determine HNE in the cerebrospinal fluid and plasma of patients with Parkinson's disease, the plasma of patients with HIV-1 infection and AIDS and in inflamed mucosal biopsy specimens from patients with inflammatory bowel disease.

A gas chromatographic--mass spectrometric study of profiles of volatile metabolites in hepatic encephalopathy.

Volatile organic substances present in blood plasma and cerebrospinal fluids of certain control groups of human subjects and cirrhotic patients some of whom were suffering from hepatic encephalopathy were quantitatively analysed and identified. A rapid, reproducible, direct injection capillary column gas chromatographic method was developed for the concentration and detection of such volatiles at mg/l and lower concentrations. Of at least forty volatiles detected, twenty-one were identified. The mean concentration of one of these, 3-methylbutanal, was found to be significantly elevated (p less than 0.01) in chronic encephalopathics (2.37 +/- 0.79 mg/l, n = 18), when compared to the controls (0.30 +/- 0.08 mg/l, n = 20). Furthermore, the concentration of this component increased with the clinically diagnosed severity of the encephalopathic state. The presence of 3-methylbutanal is related to leucine, a branched-chain amino acid linked with hepatic encephalopathy.