scholarly journals 19F Imaging of Cerebral Blood Oxygenation in Experimental Middle Cerebral Artery Occlusion: Preliminary Results

1988 ◽  
Vol 8 (2) ◽  
pp. 276-281 ◽  
Author(s):  
D. Eidelberg ◽  
G. Johnson ◽  
P. S. Tofts ◽  
J. Dobbin ◽  
H. A. Crockard ◽  
...  
Keyword(s):  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Perfusion Defect ◽  
Relaxation Times ◽  
Artery Occlusion ◽  
Blood Substitutes ◽  
Blood Oxygenation ◽  
Relative Reduction ◽  
Mca Occlusion

Fluorine (19F) nuclear magnetic resonance may be used to image cerebral perfusion in cats receiving perfluorocarbon blood substitutes. 19F relaxation times in these blood substitutes are dependent on oxygen tension (Po2) and may be used to calculate and spatially map cerebrovascular Po2 values in vivo. We have applied this noninvasive method to experimental middle cerebral artery (MCA) occlusion. Following MCA occlusion a perfusion defect is evident in the sylvian region, followed by the appearance of collaterals. Signal from the ipsilateral rete mirabilis is increased. Calculated cortical vascular Po2 values indicate a relative reduction in oxygenation in the ischaemic hemisphere. Po2 maps show a perfused hypoxaemic zone adjacent to the perfusion defect. These changes are partly reversed with reperfusion.

Acute Middle Cerebral Artery Occlusion: Experience with Volume Expansion Therapy

Neurosurgery ◽  
1986 ◽  
Vol 18 (4) ◽  
pp. 397-401 ◽  
Author(s):  
Bruce I. Tranmer ◽  
Cordell E. Gross ◽  
Ted S. Keller ◽  
Glenn W. Kindt
Keyword(s):  
Cardiac Output ◽  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Volume Expansion ◽  
Artery Occlusion ◽  
Neurological Deficits ◽  
Life Styles ◽  
Arterial Blood ◽  
Mca Occlusion ◽  
The Mean

Abstract Five consecutive patients with acute neurological deficits after middle cerebral artery (MCA) occlusion were given emergency treatment with colloidal volume expansion. In each case, the diagnosis was confirmed promptly by computed tomography and cerebral angiography. Aggressive volume expansion therapy was started 2 to 18 hours (mean, 11 hr) after the onset of the neurological deficit. The mean colloidal volume used was 920 ml/day for an average of 4 days. During volume expansion, the mean cardiac output increased 57% from 4.6 + 0.6 to 7.2 + 1.9 litres/min (P < 0.05). The mean hematocrit decreased 19% from 46 + 3% to 37 + 4% (P < 0.01). The mean arterial blood pressure remained stable, and the pulmonary artery wedge pressure was maintained at < 15 mm Hg. Three patients improved dramatically with volume expansion therapy and have returned to their previous life-styles. Two patients made partial recoveries and manage at home with nursing care. The three patients who improved dramatically were young (aged <34) and, when compared to the older patients, they had greater increases in cardiac output (67% vs. 19%). No major complications or deaths were attributed to the volume expansion therapy. We propose that intravascular volume expansion and its concomitant augmentation of the cardiovascular dynamics may be effective in the treatment of acute neurological deficits after acute MCA occlusion.

scholarly journals Cerebral Energy Metabolism Measured in vivo by 31P-NMR in Middle Cerebral Artery Occlusion in the Cat—Relation to Severity of Stroke

1987 ◽  
Vol 7 (5) ◽  
pp. 557-562 ◽  
Author(s):  
S. Komatsumoto ◽  
S. Nioka ◽  
J. H. Greenberg ◽  
K. Yoshizaki ◽  
V. H. Subramanian ◽  
...  
Keyword(s):  
Energy Metabolism ◽  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Cerebral Metabolism ◽  
Recovery Period ◽  
Creatine Phosphate ◽  
Significant Shift ◽  
Mca Occlusion ◽  
Occlusion Model

The energy metabolism of the brain has been measured in a middle cerebral artery (MCA) occlusion model in the cat utilizing 31P-nuclear magnetic resonance (NMR). 31P-NMR spectra were serially obtained during 2 h of ischemia and a subsequent 4-h recovery period. The ratio of creatine phosphate (PCr) to inorganic phosphate (Pi) (PCr/Pi) showed a precipitous decrease in parallel with changes in electroencephalographic (EEG) amplitude in severe strokes during ischemia as well as during recirculation. Animals with mild strokes, as determined by EEG criteria, exhibited a much smaller decrease in PCr/Pi during ischemia. In the severe strokes, there was a splitting and significant shift of the Pi peak immediately after occlusion. In addition, the shifted Pi peak rapidly increased and remained elevated throughout the study. In the mild strokes, Pi also increased, but not as markedly. Intracellular pH determination by chemical shift of the Pi peak revealed a decrease from 7.1 to 6.2–6.3 during ischemia and the subsequent recovery period in the animals with severe strokes, whereas the pH in the animals with mild strokes did not show a significant change. A gradual decrease in adenosine triphosphate (ATP) to 57–79% of the control was exhibited in severely stroked animals during both the ischemia and the recovery period, whereas there was no change in ATP in the mild stroked animals. These results suggest that the dynamic process of pathophysiological changes in an MCA occlusion model in the cat leads to significant differences in cerebral metabolism between animals with mild and severe strokes.

scholarly journals ARL 17477, a Potent and Selective Neuronal NOS Inhibitor Decreases Infarct Volume after Transient Middle Cerebral Artery Occlusion in Rats

1996 ◽  
Vol 16 (4) ◽  
pp. 599-604 ◽  
Author(s):  
Zheng G. Zhang ◽  
David Reif ◽  
James Macdonald ◽  
Wen Xue Tang ◽  
Dietgard K. Kamp ◽  
...  
Keyword(s):  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Cell Damage ◽  
Infarct Volume ◽  
Artery Occlusion ◽  
Arterial Blood ◽  
Mca Occlusion ◽  
Nos Inhibitor ◽  
Oxide Synthase ◽  
Cerebral Artery Occlusion

We tested the effects of administration of a selective neuronal nitric oxide synthase (nNOS) inhibitor, ARL 17477, on ischemic cell damage and regional cerebral blood flow (rCBF), in rats subjected to transient (2 h) middle cerebral artery (MCA) occlusion and 166 h of reperfusion (n = 48) and in rats without MCA occlusion (n = 25), respectively. Animals were administered ARL 17477 (i.v.): 10 mg/kg; 3 mg/kg; 1 mg/kg; N-nitro-L-arginine (L-NA) 10 mg/kg L-NA 1 mg/kg; and Vehicle. Administration of ARL 17477 1 mg/kg, 3 mg/kg and 10 mg/kg reduced ischemic infarct volume by 53 (p < 0.05), 23, and 6.5%, respectively. L-NA 1 mg/kg and 10 mg/kg increased infarct volume by 2 and 15%, respectively (p > 0.05). Administration of ARL 17477 (10 mg/kg) significantly (p < 0.05) decreased rCBF by 27 ± 5.3 and 24 ± 14.08% and cortical NOS activity by 86 ± 14.9 and 91 ± 8.9% at 10 min or 3 h, respectively, and did not alter mean arterial blood pressure (MABP). L-NA (10 mg/kg) significantly reduced rCBF by 23 ± 9.8% and NOS activity by 81 ± 7% and significantly (p < 0.05) increased MABP. Treatment with 3 mg/kg and 1 mg/kg ARL 17477 reduced rCBF by only 2.4 ± 4.5 and 0%, respectively, even when NOS activity was reduced by 63 ± 13.4 and 45 ± 15.7% at 3 h, respectively, (p < 0.05). The data demonstrate that ARL 17477 inhibits nNOS in the rat brain and causes a dose-dependent reduction in infarct volume after transient MCA occlusion.

Abstract W P93: MiR-122 Improves Stroke Outcomes after Middle Cerebral Artery Occlusion in Rats

Stroke ◽  
2015 ◽  
Vol 46 (suppl_1) ◽  
Author(s):  
DaZhi Liu ◽  
Glen C Jickling ◽  
Bradley P Ander ◽  
Heather Hull ◽  
Xinhua Zhan ◽  
...  
Keyword(s):  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Messenger Rna ◽  
Target Genes ◽  
Conflicts Of Interest ◽  
Neurological Impairment ◽  
Artery Occlusion ◽  
Neuroprotective Effects ◽  
Genomic Studies

MicroRNA (miRNA) are recently discovered small (~22 nucleotides), non-coding RNA that regulate translation of messenger RNA (mRNA) to protein. Though there are only hundreds of miRNAs, each of them can potentially regulate hundreds of target genes, via base-pairing with complementary sequences in mRNA. This provides one approach that targets a single miRNA to have effects on multiple genes. Our previous genomic studies have demonstrated that miR-122 decreased significantly in blood of experimental strokes produced by middle cerebral artery (MCA) occlusion in rats as well as in blood of patients with ischemic strokes. Therefore, we hypothesized that elevating blood miR-122 has the potential for treating stroke. Using the newly developed in vivo polyethylene glycol-liposome based miRNA transfection system and rat suture MCAO occlusion model, we show that injection of chemically modified mimic miR-122 (600ug/rat, i.v.) through tail vein immediately after MCAO occlusion significantly decreases the neurological impairment and significantly attenuates brain infarct volumes. Ongoing studies are identifying the target genes that are associated with the neuroprotective effects of miR-122 following stroke. Acknowledgements: This study was supported by NIH grant R01NS066845 (FRS). There were no conflicts of interest.

scholarly journals Blood-Oxygenation-Level-Dependent-(BOLD-) Based R2′MRI Study in Monkey Model of Reversible Middle Cerebral Artery Occlusion

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Jing Zhang ◽  
Ying-min Chen ◽  
Yun-ting Zhang
Keyword(s):  
Middle Cerebral Artery ◽  
Middle Cerebral Artery Occlusion ◽  
Time Evolution ◽  
Cerebral Artery ◽  
Artery Occlusion ◽  
Blood Oxygenation ◽  
Transverse Relaxation Rate ◽  
Additional Information ◽  
Monkey Model ◽  
Cerebral Artery Occlusion

Objective. To investigate the value of BOLD-based reversible transverse relaxation rate (R2′) MRI in detecting ischemic penumbra (IP) in a monkey model of reversible middle cerebral artery occlusion (MCAO) and time evolution of relative R2′ (rR2′) in infarcted core, IP, and oligemia.Materials and Methods. 6 monkeys were used to make MCAO by the microcatheter method. MR scans were performed at 0 h (1 h after MCAO), 1 h, 3 h, 6 h, 12 h, 24 h, and 48 h after reperfusion. R2′ was calculated using quantitative T2 and T2∗maps. Ischemic area was subdivided into infracted core, IP and oligemia. rR2′ was calculated respectively.Results. Reversible MCAO model for 4/6 monkeys was made successfully. rR2′ values were significantly different at each time point, being highest in oligemia followed by IP and infarcted core (). With reperfusion time evolution, rR2′ in infarcted core showed a decreased trend: sharply decreased within 6 hours and maintained at 0 during 6–48 hours (). rR2′ values in IP and oligemia showed similar increased trend: sharply increased within 6 hours, maintained a plateau during 6–24 hours, and slightly increased until 48 hours.Conclusion. BOLD-based R2′ MRI can be used to describe changes of cerebral oxygen extract in acute ischemic stroke, and it can provide additional information in detecting IP. The time evolution rR2′ in infarcted core, IP, and oligemia is in accordance with the underlying pathophysiology.

scholarly journals Periinfarct and Remote Excitability Changes after Transient Middle Cerebral Artery Occlusion

2000 ◽  
Vol 20 (1) ◽  
pp. 45-52 ◽  
Author(s):  
Tobias Neumann-Haefelin ◽  
Otto W. Witte
Keyword(s):  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Field Potential ◽  
Extracellular Recording ◽  
Artery Occlusion ◽  
Early Reperfusion ◽  
Paired Pulse ◽  
Mca Occlusion ◽  
Cortical Regions

Transient middle cerebral artery (MCA) occlusion results in substantially smaller cortical infarcts than permanent MCA occlusion if reperfusion is initiated within the first few hours. Only little information is available on the long-term functional outcome of the cortical regions “salvaged” by early reperfusion. To address this issue we examined basic electrophysiologic parameters in vitro using standard extracellular recording techniques at 7 and 28 days after transient MCA occlusion (1- and 2-hour ischemia) in rats. Both neocortical areas ipsi- and contralateral to MCA occlusion were systematically mapped to delineate the extent of periinfarct and remote alterations. In the periinfarct region we found a significant reduction of field potential amplitudes up to 3 mm when measuring from the infarct border at 7 days and up to 7 mm at 28 days. Paired-pulse inhibition, an indicator of GABAergic transmission, was only moderately impaired in this region at 7 days and not significantly different from control at 28 days. Remote effects were observed both ipsi- and contralaterally. Ipsilaterally they were restricted to a region close to the midline (presumably motor cortex) and were most likely attributable to the degeneration of corticostriatal connections. The extent of the contralateral excitability changes was clearly related to the size of the neocortical infarcts with large infarcts resulting in the widespread reduction of field potential amplitudes and an impairment of paired-pulse inhibition. The results show that there is a relatively large periinfarct region with decreased overall excitability after transient MCA occlusion which is likely to have a profound effect on perilesional processes involved in functional recovery. Remote excitability changes may contribute to the functional deficit and are probably related to deafferentation.

scholarly journals The IMPROVE Guidelines (Ischaemia Models: Procedural Refinements Of in Vivo Experiments)

2017 ◽  
Vol 37 (11) ◽  
pp. 3488-3517 ◽  
Author(s):  
Nathalie Percie du Sert ◽  
Alessio Alfieri ◽  
Stuart M Allan ◽  
Hilary VO Carswell ◽  
Graeme A Deuchar ◽  
...  
Keyword(s):  
Ischaemic Stroke ◽  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Artery Occlusion ◽  
Care Staff ◽  
Supplementary Information ◽  
In Vivo Models ◽  
Operative Care ◽  
Analgesic Regimen

Most in vivo models of ischaemic stroke target the middle cerebral artery and a spectrum of stroke severities, from mild to substantial, can be achieved. This review describes opportunities to improve the in vivo modelling of ischaemic stroke and animal welfare. It provides a number of recommendations to minimise the level of severity in the most common rodent models of middle cerebral artery occlusion, while sustaining or improving the scientific outcomes. The recommendations cover basic requirements pre-surgery, selecting the most appropriate anaesthetic and analgesic regimen, as well as intraoperative and post-operative care. The aim is to provide support for researchers and animal care staff to refine their procedures and practices, and implement small incremental changes to improve the welfare of the animals used and to answer the scientific question under investigation. All recommendations are recapitulated in a summary poster (see supplementary information).

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