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Query: UMLS:C0917798 (cerebral ischemia)
 17,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Basic fibroblast growth factor (bFGF) is a polypeptide that supports the survival of brain cells (including neurons, glia, and endothelia) and protects neurons against a number of toxins and insults in vitro. This factor is also a potent dilator of cerebral pial arterioles in vivo. In previous studies, we found that intraventricularly administered bFGF reduced infarct volume in a model of focal cerebral ischemia in rats. In the current study, bFGF (45 micrograms/kg/h) in vehicle, or vehicle alone, was infused intravenously for 3 h, beginning at 30 min after permanent middle cerebral artery occlusion by intraluminal suture in mature Sprague-Dawley rats. After 24 h, neurological deficit (as assessed by a 0- to 5-point scale, with 5 = most severe) was 2.6 +/- 1.0 in vehicle-treated and 1.5 +/- 1.3 in bFGF-treated rats (mean +/- SD; N = 12 vs. 11; p = 0.009). Infarct volume was 297 +/- 65 mm3 in vehicle- and 143 +/- 135 mm3 in bFGF-treated animals (p = 0.002). During infusion, there was a modest decrease in mean arterial blood pressure but no changes in arterial blood gases or core or brain temperature in bFGF-treated rats. Autoradiography following intravenous administration of 111In-labeled bFGF showed that labeled bFGF crossed the damaged blood-brain barrier to enter the ischemic (but not the nonischemic) hemisphere. Whether the infarct-reducing effects of bFGF depend on intraparenchymal or intravascular mechanisms requires further study.
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PMID:Delayed treatment with intravenous basic fibroblast growth factor reduces infarct size following permanent focal cerebral ischemia in rats. 759 56

Basic fibroblast growth factor is a polypeptide with potent multipotential trophic effects on central nervous system cells, including neurons, glia, and endothelial cells. In particular, it promotes the survival of a wide variety of brain neurons in vitro, and protects these neurons against the effects of several neurotoxins, including excitatory amino acids, hypoglycemia, and calcium ionophore. Since lack of substrate delivery, excitatory amino acid toxicity, and calcium entry into cells appear to be important processes in neuronal death after ischemia, we tested the hypothesis that pretreatment with basic fibroblast growth factor limits infarct size in a model of focal cerebral ischemia in vivo. Mature male Long-Evans rats received either continuous intraventricular infusion of basic fibroblast growth factor (1.2 micrograms/day; with or without heparin, added to stabilize the growth factor) or vehicle alone for 3 days before focal ischemic infarcts were made in the right lateral cerebral cortex by permanent distal middle cerebral artery occlusion and temporary (45-minute) bilateral carotid occlusion. Intraoperative measurements of core temperature, arterial blood pressure and blood gases, blood glucose concentration, and hematocrit, and postoperative measurements of temperature revealed no differences among vehicle- versus basic fibroblast growth factor-treated animals. Twenty-four hours later, animals were killed, brains were removed and stained to visualize cortical infarcts, and infarct volume was determined by image analysis. Overall, we found a 25% reduction in infarct volume in basic fibroblast growth factor- (N = 25) versus vehicle-treated (N = 23) animals (p < 0.01). This reduction was not enhanced by the addition of heparin.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Pretreatment with intraventricular basic fibroblast growth factor decreases infarct size following focal cerebral ischemia in rats. 815 72

The neuroprotective effect of neurotrophic factors has been demonstrated in experimental cerebral ischaemia recently. These include nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), insulin-like growth factor-1 (IGF-1), and basic fibroblast growth factor (basic FGF). The neuroprotective effect of ciliary neurotrophic factor (CNTF), however, has not been studied so far. We have examined the neuroprotective effect of recombinant rat CNTF in a rat forebrain ischaemia model. A continuous infusion of CNTF was started 1 week before the induction of ischaemia and continued until 1 week after the ischaemia. Reversible forebrain ischaemia was induced by 7 minutes of bilateral carotid occlusion with hypotension. Neuronal cell death in the hippocampal CA1 sector was evaluated 1 week after the ischaemia. For the control group artificial CSF (cerebrospinal fluid) was infused instead of CNTF. Per cent neuronal cell death was 83.4 +/- 5.9% (mean +/- SEM, n = 5) in the control group, and 71.1 +/- 10.0% (mean +/- SEM, n = 5) in the CNTF group. Although percentage of neuronal cell death was lower in the CNTF group, the difference was not statistically significant. This result suggests that the protective effect of CNTF in the rat forebrain ischaemia model may be limited compared with other neurotrophic factors. It is considered that the number of neurons protected by CNTF may be small.
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PMID:Effect of CNTF on ischaemic cell damage in rat hippocampus. 880 Mar 34

Basic fibroblast growth factor (bFGF) is a potent neurotrophic agent that promotes neuronal survival and outgrowth. Previous studies have shown that bFGF, administered intraventricularly or intravenously before or within hours after ischemia, reduces infarct size and neurological deficits in models of focal cerebral ischemia in rats. In the current study, we tested the hypothesis that bFGF, administered at later time points after ischemia, might improve behavioral recovery without affecting infarct size. Mature Sprague-Dawley rats received bFGF (1 microgram/injection) or vehicle by biweekly intracisternal injection for 4 weeks, starting at 1 day following permanent proximal middle cerebral artery (MCA) occlusion. Animals were examined every other day using four different behavioral tests to assess sensorimotor and reflex function. At 4 weeks after ischemia, there was no difference in infarct volume between bFGF- and vehicle-treated animals. There was, however, an enhancement in the rate and degree of behavioral recovery among bFGF-treated animals, as measured by all four tests. There were no apparent side effects of bFGF treatment, except that bFGF-treated animals tended to recover body weight more slowly than did vehicle-treated animals following stroke. The mechanisms of enhancement of behavioral recovery by bFGF require further study, but may include protection against retrograde neuronal death and/or stimulation of neuronal sprouting.
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PMID:Intracisternal basic fibroblast growth factor (bFGF) enhances behavioral recovery following focal cerebral infarction in the rat. 896 92

Basic fibroblast growth factor (bFGF) is a biologically active polypeptide with mitogenic, angiogenic, and neurotrophic properties. In the present study, we examined the temporal and spatial expression profiles of bFGF mRNA and protein concentration in a focal cerebral ischemia model induced by transient occlusion of the right middle cerebral artery (MCA) and both common carotid arteries (CCAs). Results of Northern blot analysis shows a transient 2.5-fold increase in the 6.0 kb transcript of bFGF mRNA within the ischemic cortex of rats subjected to 60 min ischemic insult followed by 12 h of reperfusion. Although enhanced expression of bFGF mRNA was also noted in the ipsilateral hippocampus, the temporal induction profile appeared to be different from that of the ischemic cortex. A significant increase in bFGF mRNA was observed as early as 60 min following ischemia and remained elevated for up to 2 weeks after the onset of reperfusion. In situ hybridization studies revealed constitutive expression of bFGF mRNA in discrete brain regions of sham-operated animals. Following 60 min ischemia and 12 h reperfusion, increased expression of bFGF mRNA was observed in the ischemic cortex (both peri-infarct and infarct area). Increased expression of bFGF mRNA within the infarcted area is largely confined rostrally to the outer cortical layers of the infarct, an area with increased density of blood vessels. bFGF-like immunoreactivity was also detected in areas expressing bFGF mRNA. Furthermore, a striking increase in bFGF-like immunoreactivity was observed in the ipsilateral hippocampus. Double-staining with anti-GFAP antibody indicated that the majority of the bFGF-like immunoreactivity was localized in the astrocytes, however, not all astrocytes showed bFGF-like immunoreactivity. Some GFAP negative cell also showed bFGF-like immunoreactivity. In summary, increased expression of both bFGF mRNA and immunoreactivity following ischemia were located in the same brain regions. An increase in bFGF-like immunoreactivity after ischemic insult is likely due to an increase in the expression of its 6.0 kb bFGF mRNA transcripts. Although increased bFGF mRNA was observed in both ischemic cortex and ipsilateral hippocampus after ischemic insult, the temporal expression profiles differed. Results from the present study raise the possibility that increased expression of bFGF in the peri-infarcted area may limit the spread of ischemic injury.
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PMID:Induction of basic fibroblast growth factor (bFGF) expression following focal cerebral ischemia. 938 85

Fibroblast growth factor-13 (FGF-13), novel member of FGF family has recently been molecularly cloned as a result of high throughput sequencing of a ovarian cancer cell, hippocampal, and kidney cDNA libraries. The human gene encodes for a protein with a molecular weight of 22 kDa that is most homologous to FGF-8 (70% similarity). In the current study, we tested the effects of intravenously administered FGF-13 in a model of permanent focal cerebral ischemia in Sprague-Dawley rats. FGF-13 or the vehicle was administered systematically via the tail vein 30 min prior, and 30 min and 24 h after the occlusion of the left middle cerebral artery (MCAo). Animals were weighed and evaluated behaviorally prior to and at 24 and 48 h after MCAo. The volume of cerebral infarct and swelling were determined using an image analysis system (BioQuant) and cresyl violet stained sequential sections from the forebrain region. Histopathology was evaluated to compare the therapeutic effects. We found a 63% reduction in infarct volume in FGF-13- vs. vehicle-treated animals (infarct volume was 21.9+/-3.8% in vehicle- and 8.1+/-1.6% in FGF-13-treated rats, p=0.0016) and a moderate inhibition of brain swelling by FGF-13. The reduction in infarct volume and brain swelling were associated with improvement of clinical deficits in FGF-13 treated animals (p<0.001). Histopathological examination determined that nervous tissue was better preserved in FGF-13 treated rats than those of controls. These data show that pretreatment with intravenous FGF-13 reduces infarct size and ameliorates neurological deficits following permanent focal cerebral ischemia in rats.
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PMID:Pretreatment with intravenous FGF-13 reduces infarct volume and ameliorates neurological deficits following focal cerebral ischemia in rats. 991 47

Basic fibroblast growth factor (bFGF) is a polypeptide with potent survival-promoting and protective effects on brain cells. In previous studies, we showed that intravenous administration of bFGF reduced infarct volume in models of focal cerebral ischemia in rats, mice, and cats. In these previous studies, infarct volume was measured within 1-7days of the onset of ischemia. The current study was undertaken to determine whether the reduction in infarct volume by bFGF was persistent beyond the first week after stroke. Mature male Sprague-Dawley rats received an intravenous infusion of bFGF (50 microg/kg per h) or vehicle during 0.5-3.5h after permanent proximal middle cerebral artery occlusion. We found a 27% reduction in infarct volume in bFGF- compared to vehicle-treated animals at three months after infarction (P<0.05). The data show that intravenous bFGF treatment produces a persistent reduction in infarct volume, at least up to three months following focal stroke.
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PMID:Intravenous basic fibroblast growth factor produces a persistent reduction in infarct volume following permanent focal ischemia in rats. 1117 28

The effects of cerebral ischemia on white matter changes in ovine fetuses were examined after exposure to bilateral carotid artery occlusion. Fetal sheep were exposed to 30 min of ischemia followed by 48 (I/R-48, n = 8) or 72 (I/R-72, n = 10) h of reperfusion or control sham treatment (control, n = 4). Serial coronal sections stained with Luxol fast blue/hematoxylin and eosin were scored for white matter, cerebral cortical, and hippocampal lesions. All areas received graded pathologic scores of 0 to 5, reflecting the degree of injury where 0 = 0%, 1 = 1% to 25%, 2 = 26% to 50%, 3 = 51% to 75%, 4 = 76% to 95%, and 5 = 96% to 100% of the area damaged. Dual-label immunofluorescence using antibodies against glial fibrillary acidic protein (GFAP) and myelin basic protein (MBP) were used to characterize white matter lesions. Basic fibroblast growth factor (FGF-2) was measured in the frontal cortex by ELISA. Results of the pathologic scores showed that the white matter of the I/R-72 (2.74 +/- 0.53, mean +/- SEM) was more (p < 0.05) damaged when compared with the control (0.80 +/- 0.33) group. Cortical lesions were greater (p < 0.05) in the I/R-48 (2.12 +/- 0.35) than the control (0.93 +/- 0.09) group. White matter lesions were characterized by reactive GFAP-positive astrocytes and a loss of MBP in oligodendrocytes. The ratio of MBP to GFAP decreased (p < 0.05) as a function of ischemia, indicative of a proportionally greater loss of MBP than GFAP. FGF-2 concentrations were higher (p < 0.05) in the I/R-72 than the control group and there was a direct correlation between the pathologic scores (PS) and FGF-2 concentrations (FGF-2 = e((1.6 PS-0.90)) + 743, n = 17, r = 0.73, p < 0.001). We conclude that carotid artery occlusion results in quantifiable white matter lesions that are associated with a loss of MBP from myelin, and that FGF-2, a purported mediator of recovery from brain injury in adult subjects, increases in concentration in proportion to the severity of brain damage in the fetus.
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PMID:White matter injury after cerebral ischemia in ovine fetuses. 1203 76

Basic fibroblast growth factor (bFGF) is a polypeptide with potent trophic and protective effects on the brain. bFGF has been reported to exert neuroprotection against a wide variety of insults, including ischemic neuronal injury. To date, animal models of focal ischemia have not been translated to efficacy in stroke clinically with respect to testing of neuroprotective agents. Because functional outcome is the measurement of efficacy for putative neuroprotective agents in the clinic, we sought to evaluate the functional consequences of bFGF administration in rats subjected to focal ischemia. In this study, we assessed the effects of bFGF on functional outcome as well as infarct size in rats subjected to severe cerebral ischemia by permanent occlusion of the middle cerebral artery (MCAO). Male Sprague-Dawley rats were subjected to permanent MCAO by the intraluminal filament technique. Two hours following occlusion, rats were infused intravenously with either bFGF, at a dose of 150 microg/kg, or vehicle alone. Functional sensorimotor impairment, which was assessed by the accelerating rotarod test, was recorded at baseline and compared to performance assessed at 24 h after MCAO. Permanent occlusion of the MCA caused marked impairment in rotarod performance in both groups. Treatment of rats with bFGF showed a significant 46% improvement in rotarod fall latency when compared with that from the animals treated with vehicle alone. The volume of cortical infarction was significantly reduced by 32% as a function of bFGF treatment. These results suggest that the delayed intravenous administration of bFGF improves sensorimotor function as well as reduces infarct size following permanent focal ischemia in rat.
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PMID:Postischemic administration of basic fibroblast growth factor improves sensorimotor function and reduces infarct size following permanent focal cerebral ischemia in the rat. 1242 98

Basic fibroblast growth factor (FGF-2) has been reported to protect against ischemic injury in the brains of young adult rodents. However, little is known about whether FGF-2 retains this capability in the aged ischemic brain. Since stroke in human is much more common in older people than among younger adults, to address this question is clinically important. In this study, aged (24-month-old) rats were treated with intracerebroventricular infusion of FGF-2 or vehicle for 3 days, beginning 48 h before (pre-ischemia), 24 h after (early post-ischemia), or 96 h after (late post-ischemia) 60 min of middle cerebral artery occlusion, and were killed 10 days after ischemia. Aged rats given FGF-2 pre-ischemia showed better symmetry of movement and forepaw outstretching, and reduced infarct volumes, compared to rats treated with vehicle, but no significant improvement was found in aged rats given FGF-2 after focal ischemia. In contrast, young adult (3-month-old) rats treated with FGF-2 for 3 days beginning 24 h post-ischemia showed significant neurobehavioral improvement and better histological outcome. In addition, we also found that newborn neurons in the rostral subventricular zone (SVZ) were increased in aged rats treated with FGF-2 prior to ischemia. However, unlike in young adult ischemic rats, only a few of newly generated cells migrated into the damaged region in aged brain after focal ischemia. These findings point to differences in the response of aged versus young adult rats to FGF-2 in cerebral ischemia, and suggest that such differences need to be considered in the development of neuroprotective agents for stroke.
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PMID:Influence of age on the response to fibroblast growth factor-2 treatment in a rat model of stroke. 1706 73


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