Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism
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J. Cereb. Blood Flow Metab. · Aug 2004
Celecoxib induces functional recovery after intracerebral hemorrhage with reduction of brain edema and perihematomal cell death.
The selective cyclooxygenase-2 (COX-2) inhibitor has been reported to have antiinflammatory, neuroprotective, and antioxidant effects in ischemia models. In this study, the authors examined whether a selective COX-2 inhibitor (celecoxib) reduces cerebral inflammation and edema after intracerebral hemorrhage (ICH), and whether functional recovery is sustained with longer treatment. ICH was induced using collagenase in adult rats. ⋯ Celecoxib-treated rats recovered better by the behavioral tests at 7 days after ICH throughout the 28-day period, and the earlier the drug was administered, the better the functional recovery. Evidence of similar effects in an autologous blood-injected model showed that direct collagenase toxicity was not the major cause of inflammation or cell death. These data suggest that celecoxib treatment after ICH reduces prostaglandin E2 production, brain edema, inflammation, and perihematomal cell death in the perihematomal zone and induces better functional recovery.
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J. Cereb. Blood Flow Metab. · Aug 2004
Changes in trkB-ERK1/2-CREB/Elk-1 pathways in hippocampal mossy fiber organization after traumatic brain injury.
Traumatic brain injury (TBI) leads to mossy fiber reorganization, which is considered to be a causative factor in the development of temporal lobe epilepsy. However, the underlying mechanism is not fully understood. Emerging evidence suggests that TrkB-ERK1/2-CREB/Elk-1 pathways are highly related to synaptic plasticity. ⋯ CREB was also activated at 30 minutes, peaked at 24 hours of recovery, and returned to the control level at 72 hours of recovery in dentate gyrus granule cells. Elk-1 phosphorylation was seen in CA3 neurons at 4 hours after TBI. The results suggest that the signaling pathways of TrkB-ERK1/2-CREB/Elk-1 are highly activated in mossy fiber organization, which may contribute to mossy fiber reorganization seen after TBI.
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J. Cereb. Blood Flow Metab. · Jul 2004
The effect of indomethacin on intracranial pressure, cerebral perfusion and extracellular lactate and glutamate concentrations in patients with fulminant hepatic failure.
Uncontrolled increase in intracranial pressure (ICP) continues to be one of the most significant causes of early death in patients with acute liver failure (ALF). In this study, we aimed to determine the effects of indomethacin on ICP and cerebral perfusion pressure in twelve patients with ALF and brain edema (9 females/3 males, median age 49,5 (range 21 to 64) yrs.). Also changes in cerebral perfusion determined by transcranial Doppler technique (Vmean) and jugular bulb oxygen saturation (SvjO2) were measured, as well as brain content of lactate and glutamate by microdialysis technique. ⋯ Cerebral blood flow autoregulation was impaired in all patients before injection of indomethacin, but was not restored after administration of indomethacin. We conclude that a bolus injection of indomethacin reduces ICP and increases cerebral perfusion pressure without compromising cerebral perfusion or oxidative metabolism in patients with ALF. This finding indicates that indomethacin may be valuable as rescue treatment of uncontrolled intracranial hypertension in fulminant hepatic failure.
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J. Cereb. Blood Flow Metab. · Jun 2004
Dynamic fMRI and EEG recordings during spike-wave seizures and generalized tonic-clonic seizures in WAG/Rij rats.
Generalized epileptic seizures produce widespread physiological changes in the brain. Recent studies suggest that "generalized" seizures may not involve the whole brain homogeneously. For example, electrophysiological recordings in WAG/Rij rats, an established model of human absence seizures, have shown that spike-and-wave discharges are most intense in the perioral somatosensory cortex and thalamus, but spare the occipital cortex. ⋯ During spontaneous spike-wave seizures in WAG/Rij rats under fentanylhaloperidol anesthesia, we found increased fMRI signals in focal regions including the perioral somatosensory cortex, known to be intensely involved during seizures, whereas the occipital cortex was spared. For comparison, we also studied bicuculline-induced generalized tonic-clonic seizures under the same conditions, and found fMRI increases to be larger and more widespread than during spike-and-wave seizures. These findings suggest that even in regions with intense neuronal activity during epileptic seizures, oxygen delivery exceeds metabolic needs, enabling fMRI to be used for investigation of dynamic cortical and subcortical network involvement in this disorder.
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J. Cereb. Blood Flow Metab. · Apr 2004
Delayed onset of prolonged hypothermia improves outcome after intracerebral hemorrhage in rats.
Prolonged hypothermia reduces ischemic brain injury, but its efficacy after intracerebral hemorrhagic (ICH) stroke is unresolved. Rats were implanted with core temperature telemetry probes and subsequently subjected to an ICH, which was produced by infusing bacterial collagenase into the striatum. Animals were kept normothermic (NORMO), or were made mildly hypothermic (33-35 degrees C) for over 2 days starting 1 hour (HYP-1), 6 hours (HYP-6), or 12 hours (HYP-12) after collagenase infusion. ⋯ This BRIEF treatment also resulted in significantly more bleeding at 12 hours after ICH (79.2 microL) versus NORMO-treated rats (58.4 microL) as determined by a spectrophotometric hemoglobin assay. Accordingly, these findings suggest that early hypothermia may fail to lessen lesion size owing to complications, such as elevated blood pressure, whereas much-delayed hypothermia is beneficial after ICH. Future experiments should assess whether counteracting the side effects of early hypothermia enhances protection.