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

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.

1998 ◽  
Vol 18 (2) ◽  
pp. 206-214 ◽  
Author(s):  
Yasushi Takagi ◽  
Tomoo Tokime ◽  
Kazuhiko Nozaki ◽  
Yasuhiro Gon ◽  
Haruhiko Kikuchi ◽  
...  

Thioredoxin (TRX) is a small, multifunctional protein with a redox-active site and multiple biological functions that include reducing activity for reactive oxygen intermediates. We assayed TRX and TRX mRNA by immunohistochemical methods and hybridization experiments in the rat brain after middle cerebral artery (MCA) occlusion. During ischemia, the immunoreactivity for TRX decreased; it disappeared after MCA occlusion in the ischemic regions. It rapidly decreased and nearly disappeared at 4 and 16 hours after MCA occlusion in the lateral striatum and frontoparietal cortex, respectively. On the other hand, in the perifocal ischemic region, the penumbra, TRX immunoreactivity began to increase 4 hours after MCA occlusion and continued to increase until 24 hours after occlusion. In hybridization experiments, TRX mRNA decreased and nearly disappeared 4 hours after MCA occlusion in the lateral striatum. In the frontoparietal cortex, it decreased until 24 hours after MCA occlusion. In the perifocal ischemic region, TRX mRNA began to increase 4 hours after MCA occlusion and continued to increase until 24 hours. Northern blot analysis showed that total TRX mRNA in the operated hemispheres was induced from 8 hours and increased until 24 hours after the surgical procedures. We previously reported that recombinant TRX promotes the in vitro survival of primary cultured neurons. We now suggest that TRX in the penumbra has neuroprotective functions and that decreased levels of TRX in the ischemic core modify neuronal damage during focal brain ischemia.


1994 ◽  
Vol 14 (6) ◽  
pp. 1055-1061 ◽  
Author(s):  
Hermann Theilen ◽  
Helmut Schröck ◽  
Wolfgang Kuschinsky

The densities of perfused and existing capillaries were measured in different cortical regions of rat brains after subtemporal occlusion of the middle cerebral artery (MCA). Capillary perfusion patterns (perfused capillaries versus nonperfused capillaries) were verified immediately after MCA occlusion in one group of rats and 1 h later in a second group using fluorescent double staining of capillary morphology and plasma perfusion in identical brain sections. In addition, local cerebral blood flow (CBF) was measured in another group of rats 1 h after MCA occlusion using the autoradiographic iodo-[14C]-antipyrine method. Although cortical CBF was decreased by up to 75% 1 h after MCA occlusion, plasma perfusion was not completely stopped in most capillaries (circulation time of Evans blue, 10 s). Only small patchy perfusion deficits (<0.1 mm2 of brain section) were detected in the capillaries immediately and 1 h after MCA occlusion in all brains except for one that exhibited a more extensive lack of capillary perfusion. The data show that a drastic reduction of cortical CBF after MCA occlusion is not accompanied by a corresponding amount of nonperfused capillaries.


2021 ◽  
Vol 14 (10) ◽  
pp. 966
Author(s):  
Zhiping Jia ◽  
Yunyang Liu ◽  
Xiaoru Ji ◽  
Yizheng Zheng ◽  
Zhengyang Li ◽  
...  

Scaffold-based peptides (SBPs) are fragments of large proteins that are characterized by potent bioactivity, high thermostability, and low immunogenicity. Some SBPs have been approved by the FDA for human use. In the present study, we developed SBPs from the venom gland of Deinagkistrodon acutus (D. acutus) by combining transcriptome sequencing and Pfam annotation. To that end, 10 Kunitz peptides were discovered from the venom gland of D. acutus, and most of which peptides exhibited Factor XIa (FXIa) inhibitory activity. One of those, DAKS1, exhibiting strongest inhibitory activity against FXIa, was further evaluated for its anticoagulant and antithrombotic activity. DAKS1 prolonged twofold APTT at a concentration of 15 μM in vitro. DAKS1 potently inhibited thrombosis in a ferric chloride-induced carotid-artery injury model in mice at a dose of 1.3 mg/kg. Furthermore, DAKS1 prevented stroke in a transient middle cerebral-artery occlusion (tMCAO) model in mice at a dose of 2.6 mg/kg. Additionally, DAKS1 did not show significant bleeding risk at a dose of 6.5 mg/kg. Together, our results indicated that DAKS1 is a promising candidate for drug development for the treatment of thrombosis and stroke disorders.


Neurosurgery ◽  
1986 ◽  
Vol 18 (4) ◽  
pp. 397-401 ◽  
Author(s):  
Bruce I. Tranmer ◽  
Cordell E. Gross ◽  
Ted S. Keller ◽  
Glenn W. Kindt

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 &lt; 0.05). The mean hematocrit decreased 19% from 46 + 3% to 37 + 4% (P &lt; 0.01). The mean arterial blood pressure remained stable, and the pulmonary artery wedge pressure was maintained at &lt; 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 &lt;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.


1996 ◽  
Vol 16 (4) ◽  
pp. 599-604 ◽  
Author(s):  
Zheng G. Zhang ◽  
David Reif ◽  
James Macdonald ◽  
Wen Xue Tang ◽  
Dietgard K. Kamp ◽  
...  

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.


Stroke ◽  
1997 ◽  
Vol 28 (3) ◽  
pp. 632-638 ◽  
Author(s):  
Alan R. Young ◽  
Omar Touzani ◽  
Jean-Michel Derlon ◽  
Giuliano Sette ◽  
Eric T. MacKenzie ◽  
...  

2018 ◽  
Vol 683 ◽  
pp. 207-214 ◽  
Author(s):  
Kah Ni Tan ◽  
Rebecca Hood ◽  
Kirby Warren ◽  
Debbie Pepperall ◽  
Catalina Carrasco-Pozo ◽  
...  

Molecules ◽  
2018 ◽  
Vol 23 (7) ◽  
pp. 1747 ◽  
Author(s):  
Nan Li ◽  
Lingling Feng ◽  
Yujun Tan ◽  
Yan Xiang ◽  
Ruoqi Zhang ◽  
...  

The dry root of Scutellaria baicalensis, has traditionally been applied in the treatment of cerebral ischemia in Chinese clinics. Baicalin (BA) is considered the key ingredient in it for the brain protection effects. The bioavailability of BA is very low because of its poor lipid and water solubility, which limits the therapeutic effects and clinical application. The aim of the present study was to develop a novel BA-loaded liposome (BA-LP) formulation to improve the drug lipophilicity and further to enhance the drug-concentration in the brain tissues. This study is also designed to investigate the pharmacokinetics of BA in the pathological conditions of stroke and evaluate the pharmacokinetic differences of BA caused by stroke after intravenous administration with BA and BA-LP. In this study, the novel BA-LP prepared in early stage were characterized by morphology, size, zeta potential, encapsulation rate and the in vitro release. The pharmacokinetics and biodistribution of BA and BA-LP were investigated by intravenous administration in rats with middle cerebral artery occlusion (MCAO) model and normal group respectively. BA-LP had a mean particle size of 160–190 nm, zeta potential of −5.7 mV, and encapsulation efficiency of 42 ± 1%. The BA-LP showed a sustained-release behavior, the in vitro drug-release kinetic model of BA-LP fit well with the biphasic dynamic model equation: Q = 1 − (60.12e0.56t − 59.08e0.0014t). Pharmacokinetic behavior in MCAO rats is not consistent with that of normal rats. The middle cerebral artery occlusion rats got higher Cmax and AUC0–t, which were about 1.5–2 times to normal rats both in BA and liposome groups. In addition, it got especially higher distribution in brain, while BA were not detected in brain tissues on normal rats. The Cmax and AUC0–t values were significantly greater with liposome than BA on both normal and MCAO rats. The tissue distribution behavior was significantly altered in the case of liposome administrated in comparison with BA, which the concentrations in the heart, liver, spleen, lungs and brain were all increased after administrated liposome, but decreased in kidneys. The TI values showed that the target of liposome was improved especially to heart, spleen and brain, and the brain’s target was higher in striatum and cerebellum. In conclusion, BA-LP might be a potential drug delivery system to improve the therapeutic efficacy of BA. In addition, these results also suggest that the pathological damages of ischemia-reperfusion have a significant impact on the pharmacokinetic traits of BA.


2014 ◽  
Vol 121 (1) ◽  
pp. 55-62 ◽  
Author(s):  
Bernardo Oliveira Ratilal ◽  
Mariana Moreira Coutinho Arroja ◽  
Joao Pedro Fidalgo Rocha ◽  
Adelaide Maria Afonso Fernandes ◽  
Andreia Pereira Barateiro ◽  
...  

Object There is an unmet clinical need to develop neuroprotective agents for neurosurgical and endovascular procedures that require transient cerebral artery occlusion. The aim in this study was to explore the effects of a single dose of recombinant human erythropoietin (rhEPO) before middle cerebral artery (MCA) occlusion in a focal cerebral ischemia/reperfusion model. Methods Twenty-eight adult male Wistar rats were subjected to right MCA occlusion via the intraluminal thread technique for 60 minutes under continuous cortical perfusion monitoring by laser Doppler flowmetry. Rats were divided into 2 groups: control and treatment. In the treated group, rhEPO (1000 IU/kg intravenously) was administered 10 minutes before the onset of the MCA ischemia. At 24-hour reperfusion, animals were examined for neurological deficits, blood samples were collected, and animals were killed. The following parameters were evaluated: brain infarct volume, ipsilateral hemispheric edema, neuron-specific enolase plasma levels, parenchyma histological features (H & E staining), Fluoro-Jade–positive neurons, p-Akt and total Akt expression by Western blot analysis, and p-Akt–positive nuclei by immunohistochemical investigation. Results Infarct volume and Fluoro-Jade staining of degenerating neurons in the infarct area did not vary between groups. The severity of neurological deficit (p < 0.001), amount of brain edema (78% reduction in treatment group, p < 0.001), and neuron-specific enolase plasma levels (p < 0.001) were reduced in the treatment group. Perivascular edema was histologically less marked in the treatment group. No variations in the expression or localization of p-Akt were seen. Conclusions Administration of rhEPO before the onset of 60-minute transient MCA ischemia protected the brain from this insult. It is unlikely that rhEPO pretreatment leads to direct neuronal antiapoptotic effects, as supported by the lack of Akt activation, and its benefits are most probably related to an indirect effect on brain edema as a consequence of blood-brain barrier preservation. Although research on EPO derivatives is increasing, rhEPO acts through distinct neuroprotective pathways and its clinical safety profile is well known. Clinically available rhEPO is a potential therapy for prevention of neuronal injury induced by transitory artery occlusion during neurovascular procedures.


2014 ◽  
Vol 121 (3) ◽  
pp. 631-636 ◽  
Author(s):  
Satoshi Kiyofuji ◽  
Tomohiro Inoue ◽  
Hirotaka Hasegawa ◽  
Akira Tamura ◽  
Isamu Saito

Embolic intracranial large artery occlusion with severe neurological deficit is associated with an extremely poor prognosis. The safest and most effective treatment strategy has not yet been determined when such emboli are associated with unstable proximal carotid plaque. The authors performed emergent surgical embolectomy for left middle cerebral artery (MCA) occlusion, and the patient experienced marked neurological recovery without focal deficit and regained premorbid activity. Postoperative investigation revealed “vulnerable plaque” of the left internal carotid artery without apparent evidence of cardiac embolism, such as would be seen with atrial fibrillation. Specimens from subsequent elective carotid endarterectomy (CEA) showed ruptured vulnerable plaque that was histologically consistent as a source of the intracranial embolic specimen. Surgical embolectomy for MCA occlusion due to carotid plaque rupture followed by CEA could be a safer and more effective alternative to endovascular treatment from the standpoint of obviating the risk of secondary embolism that could otherwise occur as a result of the manipulation of devices through an extremely unstable portion of plaque. Further, this strategy is associated with a high probability of complete recanalization with direct removal of hard and large, though fragile, emboli.


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