Jul
01
2010
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The role of proteomics in the diagnosis of chorioamnionitis and early-onset neonatal sepsis.

Intrauterine infection is a unique pathologic process that raises the risk for early-onset neonatal sepsis (EONS). By acting synergistically with prematurity, EONS increases the risk for adverse neonatal outcomes, including intraventricular hemorrhage and cerebral palsy. Although several pathways for the pathogenesis of fetal damage have been proposed, the basic molecular mechanisms that modulate these events remain incompletely understood. Discovery of clinically and biologically relevant biomarkers able to reveal key pathogenic pathways and predict pregnancies at risk for antenatal fetal damage is a priority. Proteomics provides a unique opportunity to fill this gap.

Written by admin in: Cerebral Palsy |
Jul
01
2010
0

A case of subarachnoid hemorrhage with pituitary apoplexy caused by idiopathic hypertrophic pachymeningitis.

Steroid therapy is considered to improve clinical symptoms in hypertrophic pachymeningitis. We present a 70-year-old man with idiopathic hypertrophic pachymeningitis, whose clinical signs progressively worsened despite steroid therapy. He died of subarachnoid hemorrhage (SAH) with pituitary apoplexy 2 months after the admission regardless of improvement of laboratory data and magnetic resonance imaging appearance by one-and-half-month steroid therapy. Autopsy revealed thickened dura mater supporting the diagnosis of hypertrophic pachymeningitis. Brain parenchyma is generally not affected by the disease; however, histological investigation suggested that inflammation of the dura caused damage to superior hypophyseal artery resulting in SAH and apoplexy in the anterior lobe of the pituitary gland. The higher dose and the longer duration of steroid therapy should have achieved in our case although most laboratory data recovered within the normal range. The aggressiveness of hypertrophic pachymeningitis must be evaluated by clinical signs rather than by laboratory data or imaging examinations.

Written by admin in: Brain Damage |
Jul
01
2010
0

CT and MR in non-neonatal hypoxic-ischemic encephalopathy: radiological findings with pathophysiological correlations.

Non-neonatal hypoxic-ischemic encephalopathy is a clinical condition often related to cardiopulmonary arrest that demands critical management and treatment decisions. Management depends mainly on the degree of neurological impairment and prognostic considerations. Computed tomography (CT) is often used to exclude associated or mimicking pathology. If any, only nonspecific signs such as cerebral edema, sulci effacement, and decreased gray matter (GM)/white matter (WM) differentiation are evident. Pseudosubarachnoid hemorrhage, a GM/WM attenuation ratio <1.18, and inverted GM attenuation are associated with a poor prognosis. Magnetic resonance (MR) imaging is more sensitive than CT in assessing brain damage in hypoxic-ischemic encephalopathy. Some MR findings have similarities to those seen pathologically, based on spatial distribution and time scale, such as lesions distributed in watershed regions and selective injury to GM structures. In the acute phase, lesions are better depicted using diffusion-weighted imaging (DWI) because of the presence of cytotoxic edema, which, on T2-weighted images, only become apparent later in the early subacute phase. In the late subacute phase, postanoxic leukoencephalopathy and contrast enhancement could be observed. In the chronic phase, atrophic changes predominate over tissue signal changes. MR can be useful for estimating prognosis when other tests are inconclusive. Some findings, such as the extent of lesions on DWI and presence of a lactate peak and depleted N-acetyl aspartate peak on MR spectroscopy, seem to have prognostic value.

Written by admin in: Brain Damage |
Jul
01
2010
0

Cholecystokinin/Cholecystokinin-1 Receptor-Mediated Peripheral Activation of the Afferent Vagus by Enteral Nutrients Attenuates Inflammation in Rats.

OBJECTIVE:: The current study investigates activation of the nutritional anti-inflammatory pathway by lipid-rich nutrition. BACKGROUND:: Enteral nutrition activates humoral and neural pathways to regulate food intake and sustain energy balance. Recently, we demonstrated that enteral nutrition and in particular lipid-rich nutrition modulates inflammation and prevents organ damage. METHODS:: Male rats were fasted or fed lipid-rich nutrition before hemorrhagic shock. Disruption of afferent vagal fibers with capsaicin (deafferentation) was used to investigate involvement of afferent fibers. Peripheral activation of afferent vagal fibers via cholecystokinin (CCK)-mediated activation of CCK-1 receptors was investigated using administration of the selectively peripheral acting CCK-1 receptor antagonist, A70104 and PEGylated-CCK9. Tissue and blood were collected 90 minutes after shock to assess systemic inflammation and intestinal integrity. RESULTS:: Deafferentation reversed the inhibitory effect of lipid-rich nutrition on systemic levels of tumor necrosis factor-alpha and interleukin-6, and on intestinal leakage of horseradish peroxidase and bacterial translocation. Furthermore, the protective effects of lipid-rich nutrition were negated by A70104, indicating that lipid-rich nutrition triggers peripheral CCK-1 receptors on vagal afferents to modulate inflammation. These findings were substantiated by the fact that pretreatment of fasted rats with PEGylated-CCK9, which acts on peripheral CCK-1 receptors, attenuated systemic inflammation, and loss of intestinal integrity. CONCLUSION:: These data demonstrate that enteral lipid-rich nutrition modulates inflammation and preserves intestinal integrity via CCK release which activates CCK-1 receptors located on afferent vagal fibers. Taken together, the current study reveals a novel gut-brain-immune axis and provides new insight into the applicability of enteral nutrition to treat inflammatory conditions.

Written by admin in: Brain Damage |
Jul
01
2010
0

Is cerebral oxygen supply compromised in preterm infants undergoing surgical closure for patent ductus arteriosus?

Background A haemodynamically important patent ductus arteriosus (PDA) is a risk factor for brain damage in preterm infants. The authors previously reported lower regional cerebral oxygen saturation (rScO(2)) in infants with PDA, which recovered after administration of indomethacin. However, PDA ligation has been reported to pose an even higher risk of neurodevelopmental impairment. Objective To investigate the impact of surgical closure of PDA on rScO(2) and cerebral fractional tissue oxygen extraction (cFTOE), measured by near-infrared spectroscopy, and on amplitude-integrated electro-encephalography (aEEG) measured brain activity. Design/methods In 20 preterm infants (gestational age 24.7-30.4 weeks; birth weight 630-1540 g), blood pressure, arterial saturation, rScO(2), cFTOE and aEEG were monitored before, during and up to 24 h after surgery. Results Before surgery, median (range) rScO(2) was 53% (41-68%), and during surgery, but before ductal clipping, it was 46% (31-89%). Eleven infants showed a drop in blood pressure and 13 infants a drop in rScO(2) during surgery (range 2-21%), accompanied by a decrease in aEEG amplitude. Twelve infants had rScO(2) values below 50% during surgery, with five being below 40%. Only at 24 h after surgery was rScO(2) higher (61% (36-85%), p<0.05) and cFTOE values lower (0.38 (0.09-0.61); p<0.05) compared with preclipping values. Conclusion Ductal ligation poses a risk for a further decrease in already compromised cerebral oxygenation in preterm infants.

Written by admin in: Brain Damage |
Jul
01
2010
0

Association of anti-triosephosphate isomerase antibody and MRL/MpJ-Fas(lpr) mouse.

The association between anti-triosephosphate isomerase (TPI) antibodies and MRL/MpJ-Fas(lpr) (MRL/lpr) mice was examined. We found that serum anti-TPI antibody levels in MRL/lpr mice, measured by enzyme-linked immunosorbent assay, were significantly higher than that of age-matched Balb/c mice and NZB/WF1 mice. Anti-TPI antibodies were detected in serum and cerebrospinal fluid in MRL/lpr mice by Western blotting. Inoculation of anti-TPI monoclonal antibody-producing hybridoma into the brain of Balb/c mice resulted in immunoglobulin deposition in the regions near the ventricles, hippocampus, and choroid plexus. Anti-TPI antibodies may play a role in the etiology of brain damage and behavioral deficits in MRL/lpr mice. Copyright © 2010 Elsevier B.V. All rights reserved.

Written by admin in: Brain Damage |
Jul
01
2010
0

Herpes simplex virus induces neural oxidative damage via microglial cell Toll-like receptor-2.

ABSTRACT: BACKGROUND: Using a murine model of herpes simplex virus (HSV)-1 encephalitis, our laboratory has determined that induction of proinflammatory mediators in response to viral infection is largely mediated through a Toll-like receptor-2 (TLR2)-dependent mechanism. Published studies have shown that, like other inflammatory mediators, reactive oxygen species (ROS) are generated during viral brain infection. It is increasingly clear that ROS are responsible for facilitating secondary tissue damage during central nervous system infection and may contribute to neurotoxicity associated with herpes encephalitis. METHODS: Purified microglial cell and mixed neural cell cultures were prepared from C57B/6 and TLR2-/- mice. Intracellular ROS production in cultured murine microglia was measured via 2′ ,7′-Dichlorofluorescin diacetate (DCFH-DA) oxidation. An assay for 8-isoprostane, a marker of lipid peroxidation, was utilized to measure free radical-associated cellular damage. Mixed neural cultures obtained from beta-actin promoter-luciferase transgenic mice were used to detect neurotoxicity induced by HSV-infected microglia. RESULTS: Stimulation with HSV-1 elevated intracellular ROS in wild-type microglial cell cultures, while TLR2-/- microglia displayed delayed and attenuated ROS production following viral infection. HSV-infected TLR2-/- microglia produced less neuronal oxidative damage to mixed neural cell cultures in comparison to HSV-infected wild-type microglia. Further, HSV-infected TLR2-/- microglia were found to be less cytotoxic to cultured neurons compared to HSV-infected wild-type microglia. These effects were associated with decreased activation of p38 MAPK and p42/p44 ERK in TLR2-/- mice. CONCLUSIONS: These studies demonstrate the importance of microglial cell TLR2 in inducing oxidative stress and neuronal damage in response to viral infection.

Written by admin in: Brain Damage |
Jul
01
2010
0

ULCERATIVE COLITIS EXACERBATES LPS-INDUCED DAMAGE TO THE NIGRAL DOPAMINERGIC SYSTEM: POTENTIAL RISK FACTOR IN PARKINSON;S DISEASE.

ABSTRACT Peripheral inflammation could play a role in the origin and development of certain neurodegenerative disorders. To ascertain this possibility, a model of dopaminergic neurodegeneration based on the injection of the inflammatory agent lipopolysaccharide (LPS) within the substantia nigra (SN) was assayed in rats with ulcerative colitis (UC) induced by the ingestion of dextran sulphate sodium. We found an increase in the levels of inflammatory markers from serum (TNF-alpha, IL-1beta, IL-6 and the acute phase protein C-reactive protein) and SN (TNF-alpha, IL-1beta, IL-6, iNOS, ICAM-1, microglial and astroglial populations) of rats with UC, as well as an alteration of the blood-brain barrier permeability and the loss of dopaminergic neurons. UC reinforced the inflammatory and deleterious effects of LPS. On the contrary, clodronate encapsulated in liposomes (ClodLip), which depletes peripheral macrophages, ameliorated the effect of LPS and UC. Peripheral inflammation might represent a risk factor in the development of Parkinson’s disease.

Written by admin in: Brain Damage |
Jul
01
2010
0

Nogo-A antibodies and training reduce muscle spasms in spinal cord-injured rats.

OBJECTIVE: Spinal cord injury (SCI) leads to permanent motor and sensory deficits due to the damage of ascending and descending fiber tracts. In addition, malfunctions such as neuropathic pain or muscle spasms develop in many patients, possibly caused by injury-induced plastic changes of neuronal circuits above and below the lesion. New treatment strategies for spinal cord injury aim at enhancing plasticity and neurite growth, for example, by blocking the key neurite growth inhibitor Nogo-A or its downstream effectors. It is therefore crucial to investigate potential effects of such treatments on malfunctions such as muscle spasms. In addition, locomotor training, now a standard therapeutic tool to improve walking ability in incomplete SCI subjects, can be expected to influence the rearrangement of spinal cord circuits and the development of muscle spasms and other malfunctions. METHODS AND RESULTS: Here we present and validate a new rat model for muscle spasms after incomplete SCI and show that both intrathecal anti-Nogo-A antibody treatment and locomotor training, started early after injury, permanently reduce the development of muscle spasms. INTERPRETATION: The results show that an antibody-mediated suppression of the growth inhibitory protein Nogo-A leads to functional recovery and a lower level of malfunctions, suggesting the formation of functionally meaningful connections in the damaged spinal cord. Treadmill training early after SCI also has a beneficial effect. ANN NEUROL 2010;68:48-57.

Written by admin in: Brain Damage |
Jul
01
2010
0

Replication stress and oxidative damage contribute to aberrant constitutive activation of DNA damage signalling in human gliomas.

Malignant gliomas, the deadliest of brain neoplasms, show rampant genetic instability and resistance to genotoxic therapies, implicating potentially aberrant DNA damage response (DDR) in glioma pathogenesis and treatment failure. Here, we report on gross, aberrant constitutive activation of DNA damage signalling in low- and high-grade human gliomas, and analyze the sources of such endogenous genotoxic stress. Based on analyses of human glioblastoma multiforme (GBM) cell lines, normal astrocytes and clinical specimens from grade II astrocytomas (n=41) and grade IV GBM (n=60), we conclude that the DDR machinery is constitutively activated in gliomas, as documented by phosphorylated histone H2AX (gammaH2AX), activation of the ATM-Chk2-p53 pathway, 53BP1 foci and other markers. Oxidative DNA damage (8-oxoguanine) was high in some GBM cell lines and many GBM tumors, while it was low in normal brain and grade II astrocytomas, despite the degree of DDR activation was higher in grade II tumors. Markers indicative of ongoing DNA replication stress (Chk1 activation, Rad17 phosphorylation, replication protein A foci and single-stranded DNA) were present in GBM cells under high- or low-oxygen culture conditions and in clinical specimens of both low- and high-grade tumors. The observed global checkpoint signaling, in contrast to only focal areas of overabundant p53 (indicative of p53 mutation) in grade II astrocytomas, are consistent with DDR activation being an early event in gliomagenesis, initially limiting cell proliferation (low Ki-67 index) and selecting for mutations of p53 and likely other genes that allow escape (higher Ki-67 index) from the checkpoint and facilitate tumor progression. Overall, these results support the potential role of the DDR machinery as a barrier to gliomagenesis and indicate that replication stress, rather than oxidative stress, fuels the DNA damage signalling in early stages of astrocytoma development.Oncogene advance online publication, 28 June 2010; doi:10.1038/onc.2010.249.

Written by admin in: Brain Damage |

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