Jul
06
2009
0

Relationship between elevated cerebrospinal fluid levels of plasminogen activator inhibitor 1 and neuronal destruction in patients with neuropsychiatric systemic lupus erythematosus.

OBJECTIVE: A homeostatic imbalance between coagulation and fibrinolysis might occur intrathecally in neuropsychiatric systemic lupus erythematosus (NPSLE). However, there are no published data on levels of fibrinolytic factors in the cerebrospinal fluid (CSF) of patients with NPSLE. The present study was undertaken to assess CSF levels of fibrinolytic molecules, including urokinase plasminogen activator (uPA), tissue plasminogen activator (tPA), D-dimer, and plasminogen activator inhibitor 1 (PAI-1), in SLE patients with clinically verified neuropsychiatric involvement and to compare these levels with those in SLE patients without neuropsychiatric involvement and in healthy subjects. METHODS: Levels of uPA, tPA, and PAI-1 were assessed in CSF from 94 patients with SLE (33 who had NPSLE, 56 who did not have NPSLE, and 5 who were positive for antiphospholipid antibody [not included in the NPSLE or non-NPSLE group]) and from 53 age-matched controls. Patients were evaluated clinically, with magnetic resonance imaging of the brain, analyses of neuronal/glial degradation products in CSF, and neuropsychiatric testing. RESULTS: In the group of patients with NPSLE, intrathecal PAI-1 levels were significantly elevated compared with levels in SLE patients without overt neuropsychiatric involvement (P < 0.05) and in healthy controls (P < 0.001). In contrast, intrathecal levels of uPA did not differ significantly. Intrathecal levels of PAI-1 correlated significantly with CSF levels of interleukin-6 (IL-6) (r = 0.34, P < 0.001) and IL-8 (r = 0.33, P < 0.001). Importantly, increased PAI-1 and D-dimer levels were observed in SLE patients who had pathologically elevated levels of glial fibrillary acidic protein, neurofilament triplet protein, and tau protein in CSF. CONCLUSION: Intrathecal release of PAI-1 is increased in patients with NPSLE. This results in impaired fibrinolysis, which might contribute to neuronal and astrocytic damage in NPSLE.

Written by admin in: Brain Damage |
Jul
06
2009
0

Early nerve ending rescue from oxidative damage and energy failure by L: -carnitine as post-treatment in two neurotoxic models in rat: recovery of antioxidant and reductive capacities.

Cell rescue is a primary need during acute and chronic insults to the central nervous system. Functional preservation during the early stages of toxicity in a given degenerative event may represent a significant amelioration of detrimental processes linked to neuronal cell loss. Excitotoxicity and depleted cellular energy are toxic events leading to cell death in several neurodegenerative disorders. In this work, the effects of the well-known antioxidant and energy precursor, L: -carnitine (L: -CAR), were tested as a post-treatment in two neurotoxic models under in vitro and in vivo conditions. The experimental models tested included: (1) a typical excitotoxic and pro-oxidant inducer, quinolinic acid (QUIN); and (2) a mitochondrial energy inhibitor, 3-nitropropionic acid (3-NP). For in vitro studies, increasing concentrations of L: -CAR (10-1,000 muM) were added to the isolated brain synaptosomes at different times (1, 3 and 6 h) after the incubation with toxins (100 muM QUIN and 1 mM 3-NP), and 30 min later, lipid peroxidation (LP) and mitochondrial dysfunction (MD) were evaluated. For in vivo purposes, L: -CAR (100 mg/kg, i.p.) was given to rats either as a single administration 120 min after the intrastriatal infusion of QUIN (240 nmol/mul) or 3-NP (500 nmol/mul), or for 7 consecutive days (starting 120 min post-lesion). LP and MD were evaluated 4 h and 7 days post-lesions in isolated striatal synaptosomes. Our results show that, despite some variations depending on the toxic model tested, the time of exposure, or the biomarker evaluated, nerve ending protection can be mostly achieved by L: -CAR within the first hours after the toxic insults started, suggesting that targeting the ongoing oxidative damage and/or energy depletion during the first stages of neurotoxic events is essential to rescue nerve endings.

Written by admin in: Brain Damage |
Jul
06
2009
0

Do Vacuum-Assisted Deliveries Cause Intracranial Vessel Injuries?

Vacuum-assisted deliveries are fairly commonly used in obstetrical practice. Most newborns who have a vacuum-assisted delivery undergo extracranial birth traumas that have no residual consequences. Vacuum-assisted deliveries that complicate intracranial vascular infarction are rarely reported. We present 2 cases of intracranial vessel infarction after vacuum-assisted deliveries. One newborn, with scalp erosion, showed an unusual left middle cerebral artery infarct, and the other, with a severe subgaleal hematoma, had a venous thrombosis. Before the diagnosis, made using brain ultrasonography, neither had specific observable neurological symptoms. In conclusion, vacuum-assisted deliveries should be given special attention, especially when they are combined with a severe extracranial birth trauma.

Written by admin in: Brain Damage |
Jul
06
2009
0

Maternal Allopurinol During Fetal Hypoxia Lowers Cord Blood Levels of the Brain Injury Marker S-100B.

BACKGROUND: Fetal hypoxia is an important determinant of neonatal encephalopathy caused by birth asphyxia, in which hypoxia-induced free radical formation plays an important role. HYPOTHESIS: Maternal treatment with allopurinol, will cross the placenta during fetal hypoxia (primary outcome) and reduce S-100B and free radical formation (secondary outcome). METHODS: In a randomized, double-blind feasibility study, 53 pregnant women in labor (54 fetuses) with a gestational age of >36 weeks and fetal hypoxia, as indicated by abnormal/nonreassuring fetal heart rate tracing or fetal scalp pH of <7.20, received 500 mg of allopurinol or placebo intravenously. Severity of fetal hypoxia, brain damage and free radical formation were assessed by arterial cord blood lactate, S-100B and non-protein-bound-iron concentrations, respectively. At birth, maternal and cord blood concentrations of allopurinol and its active metabolite oxypurinol were determined. RESULTS: Allopurinol and oxypurinol concentrations were within the therapeutic range in the mother (allopurinol > 2 mg/L and/or oxypurinol > 4 mg/L) but not always in arterial cord blood. We therefore created 3 groups: a placebo (n = 27), therapeutic allopurinol (n = 15), and subtherapeutic allopurinol group (n = 12). Cord lactate concentration did not differ, but S-100B was significantly lower in the therapeutic allopurinol group compared with the placebo and subtherapeutic allopurinol groups (P < .01). Fewer therapeutic allopurinol cord samples had measurable non-protein-bound iron concentrations compared with placebo (P < .01). CONCLUSIONS: Maternal allopurinol/oxypurinol crosses the placenta during fetal hypoxia. In fetuses/newborns with therapeutic allopurinol/oxypurinol concentrations in cord blood, lower plasma levels of the brain injury marker protein S-100B were detected. A larger allopurinol trial in compromised fetuses at term seems warranted. The allopurinol dosage must be adjusted to achieve therapeutic fetal allopurinol/oxypurinol concentrations.

Written by admin in: Brain Damage |
Jul
06
2009
0

Pegylated nanoliposomes remote-loaded with the antioxidant tempamine ameliorate experimental autoimmune encephalomyelitis.

Reactive oxygen species are involved in the pathogenesis of multiple sclerosis (MS), Parkinson’s disease and neurodegenerative diseases. Here we report that Tempamine (TMN), a stable radical with antioxidant and proapoptotic activities, when encapsulated in the intraliposome aqueous phase of pegylated (<100 nm) nanoliposomes (nSSL), is efficient in inhibiting experimental autoimmune encephalomyelitis (EAE) in mice. The TMN is remote-loaded into nSSL by an intraliposome high/extraliposome low transmembrane ammonium sulfate gradient. Biodistribution studies of nSSL-TMN labeled with the liposome non transferable non metabolizable (3)H-cholesteryl hexadecyl ether show that almost 3% of the injected dose of liposomes reached the brain of the EAE mice, compared with less than 1% in the control healthy mice. This accumulation in the brain, combined with the fact that TMN demonstrates a controlled slow release out of the nSSL, may explain the superior therapeutic activity of nSSL-TMN over free TMN. Our results suggest that the study of nSSL-TMN for therapy of MS, and other neurodegenerative diseases involving oxidative damage, is worth pursuing.

Written by admin in: Brain Damage |
Jul
06
2009
0

Neurobehavioral impairments, generation of oxidative stress and release of pro-apoptotic factors after chronic exposure to Sulphur Mustard in mouse brain.

Recent global events have focused attention on the potential threat of international and domestic chemical terrorism, as well as the possibility of chemical warfare proliferation. Sulphur mustard (SM) is one of the potent Chemical Warfare Agent (CWA), which initiates a cascade of events that converge on the redox mechanisms common to brain injury. The present study was designed to examine the effects of chronic SM exposure on neurobehavioral impairments, mitochondrial oxidative stress in male Swiss Albino mice and its role in inducing apoptotic neuronal cell death. The animals were divided into four groups (control, low, medium and high dose) of 5 animals each. Exposure to SM was given per cutaneous daily for 12 weeks. The results demonstrated impairment in neurobehavioral indices viz. rota rod, passive avoidance and water maze tests in a dose dependent manner. There was significant increase in lipid peroxidation and protein carbonyl content whereas, decrease in the activity of manganese superoxide dismutase (MnSOD), glutathione reductase and glutathione peroxidase suggesting impaired antioxidant defense system. Immunoblotting of cytochrome c, Bcl-2, Bax and activation of caspase-3 suggest induction of apoptosis in a dose dependent manner. Finally, increased p53 expression suggests it may target the mitochondrial pathway for inducing apoptosis in response to DNA damage signals. In conclusion, chronic SM exposure may have the potential to generate oxidative stress which may trigger the release of cytochrome c as well as caspase-3 activation in neurons leading to cell death by apoptosis in a dose dependent manner which may in the end responsible for the disruption of cognitive functions in mice.

Written by admin in: Brain Damage |
Jul
06
2009
0

Aerobic Fitness is Associated with Gray Matter Volume and White Matter Integrity in Multiple Sclerosis.

Alterations in gray and white matter have been well documented in individuals with multiple sclerosis. Severity and extent of such brain tissue damage have been associated with cognitive impairment, disease duration and neurological disability, making quantitative indices of tissue damage important markers of disease progression. In this study, we investigated the association between cardiorespiratory fitness and measures of gray matter atrophy and white matter integrity. Employing a voxel-based approach to analyses of gray matter and white matter, we specifically examined whether higher levels of fitness in multiple sclerosis participants were associated with preserved gray matter volume and integrity of white matter. We found a positive association between cardiorespiratory fitness and regional gray matter volumes and higher focal fractional anisotropy values. Statistical mapping revealed that higher levels of fitness were associated with greater gray matter volume in the midline cortical structures including the medial frontal gyrus, anterior cingulate cortex and the precuneus. Further, we also found increasing levels of fitness were associated with higher fractional anisotropy in the left thalamic radiation and right anterior corona radiata. Both preserved gray matter volume and white-matter tract integrity were associated with better performance on measures of processing speed. Taken together, these results suggest that fitness exerts a prophylactic influence on the cerebral atrophy observed early on preserving neuronal integrity in multiple sclerosis, thereby reducing long-term disability.

Written by admin in: Brain Damage |
Jul
06
2009
0

Adenosine deaminase activity, lipid peroxidation and astrocyte responses in the cerebral cortex of rats after neonatal hypoxia ischemia.

Hypoxia ischemia (HI) is a common cause of damage in the fetal and neonatal brain. Lifelong disabilities such as cerebral palsy, epilepsy, behavioral and learning disorders are some of the consequences of brain injury acquired in the perinatal periods. Inflammation and formation of free radicals appear to play key roles in neonatal HI. The aim of this study was to describe the chronological sequence of adenosine deaminase (ADA) activity, the oxidative damage changes and astrocyte response using the classic model of neonatal HI. We observed an increase in the activity of ADA and lipid peroxidation in the cerebral cortex eight days after neonatal HI. This was accompanied by a GFAP-positive, and the degree of brain damage was determined histochemically by hematoxylin-eosin (HE). Taking into account the important anti-inflammatory role of adenosine, ADA may provide an efficient means for scavenging cell-surrounding adenosine and play an important part in subsequent events of neonatal HI in association with GFAP reactive gliosis. The present investigation showed that neonatal HI causes the increase of free radicals and significant damage in the cerebral cortex. The increase in ADA activity may reflect the activation of the immune system caused by HI because the morphological analysis exhibited a lymphocytic infiltration.

Written by admin in: Brain Damage |
Jul
06
2009
0

Predictors of hematological abnormalities in patients with chronic hepatitis C treated with interferon and ribavirin.

Hematological abnormalities including neutropenia, anemia, and thrombocytopenia are commonly seen in patients with chronic hepatitis C treated with pegylated interferon and ribavirin. The aim of this study was to identify factors which would help to predict the development of hematological abnormalities in patients with chronic hepatitis C treated with pegylated interferon and ribavirin. During a 4-year period, all patients with chronic hepatitis C started on treatment with pegylated interferon and ribavirin were identified. Patients were defined as having hematological abnormalities if they had the presence of either anemia, neutropenia, thrombocytopenia, or a combination of the above during treatment with pegylated interferon and ribavirin. A total of 136 patients with chronic hepatitis C were included in this study. Fifty-two (38.2%) of the patients developed significant hematological abnormalities during treatment with pegylated interferon and ribavirin with 28 (20.6%), 30 (22.1%), and 11 (8.1%) developed neutropenia, anemia, and thrombocytopenia, respectively. Genotype 1, history of hypertension, low baseline platelet count, low baseline hemoglobin, as well as a raised creatinine were significant factors associated with the development of hematological abnormalities. Significant hematological abnormalities are commonly present in patients with chronic hepatitis C treated with pegylated interferon and ribavirin. This study identifies pretreatment parameters that may help identify high-risk patients who are more likely to develop hematological abnormalities during treatment for chronic hepatitis C.

Written by admin in: Ischemic Brain Damage |
Jul
06
2009
0

Molecular imaging of hypoxia with radiolabelled agents.

Tissue hypoxia results from an inadequate supply of oxygen (O(2)) that compromises biological functions. Structural and functional abnormalities of the tumour vasculature together with altered diffusion conditions inside the tumour seem to be the main causes of tumour hypoxia. Evidence from experimental and clinical studies points to a role for tumour hypoxia in tumour propagation, resistance to therapy and malignant progression. This has led to the development of assays for the detection of hypoxia in patients in order to predict outcome and identify patients with a worse prognosis and/or patients that would benefit from appropriate treatments. A variety of invasive and non-invasive approaches have been developed to measure tumour oxygenation including oxygen-sensitive electrodes and hypoxia marker techniques using various labels that can be detected by different methods such as positron emission tomography (PET), single photon emission computed tomography (SPECT), magnetic resonance imaging (MRI), autoradiography and immunohistochemistry. This review aims to give a detailed overview of non-invasive molecular imaging modalities with radiolabelled PET and SPECT tracers that are available to measure tumour hypoxia.

Written by admin in: Ischemic Brain Damage |

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