ABSTRACT
Over the preceding decades, there have been substantial advances in our knowledge of the pathophysiology of stroke. One such advance has been an increased understanding of the multifarious crosstalk in which the nervous and immune systems engage in order to maintain homeostasis. By interrupting the immune-nervous nexus, it is thought that stroke induces change in both systems. Additionally, it has been found that both innate and adaptive immunosuppression play protective roles against the effects of stroke. The release of danger-/damage-associated molecular patterns (DAMPs) activates Toll-like receptors (TLRs), contributing to the harmful inflammatory effects of ischemia/reperfusion injury after stroke; the Tyro3, Axl, and MerTK (TAM)/Gas6 system, however, has been shown to suppress inflammation via downstream signaling molecules that inhibit TLR signaling. Anti-inflammatory cytokines have also been found to promote neuroprotection following stroke. Additionally, adaptive immunosuppression merits further consideration as a potential endogenous protective mechanism. In this review, we highlight recent studies regarding the effects and mechanism of immunosuppression on the pathophysiology of stroke, with the hope that a better understanding of the function of both of innate and adaptive immunity in this setting will facilitate the development of effective therapies for post-stroke inflammation.
ABSTRACT
Over the preceding decades, there have been substantial advances in our knowledge of the pathophysiology of stroke. One such advance has been an increased understanding of the multifarious crosstalk in which the nervous and immune systems engage in order to maintain homeostasis. By interrupting the immune-nervous nexus, it is thought that stroke induces change in both systems. Additionally, it has been found that both innate and adaptive immunosuppression play protective roles against the effects of stroke. The release of danger-/damage-associated molecular patterns (DAMPs) activates Toll-like receptors (TLRs), contributing to the harmful inflammatory effects of ischemia/reperfusion injury after stroke; the Tyro3, Axl, and MerTK (TAM)/Gas6 system, however, has been shown to suppress inflammation via downstream signaling molecules that inhibit TLR signaling. Anti-inflammatory cytokines have also been found to promote neuroprotection following stroke. Additionally, adaptive immunosuppression merits further consideration as a potential endogenous protective mechanism. In this review, we highlight recent studies regarding the effects and mechanism of immunosuppression on the pathophysiology of stroke, with the hope that a better understanding of the function of both of innate and adaptive immunity in this setting will facilitate the development of effective therapies for post-stroke inflammation.
ABSTRACT
Objective@#To explore the long-term effect of neuroendoscopy followed by radiotherapy on cystic craniopharyngiomas.@*Methods@#Cystic craniopharyngiomas in 9 patients were treated with neuroendoscopic cyst aspiration and fenestration, followed by fractionated stereotactic radiotherapy (FSRT). The neuroendoscopic procedure focused on widening of cyst fenestration and extensive irrigation of the cyst contents. The collimator of FSRT ranged from 2.5 cm to 3.0 cm, and the target volume 1.1-43.8 cm3, dose per fraction 1.8 Gy, total dose 50.4 Gy.@*Results@#The median follow-up period was 72.9 months. Tumor control was achieved in 8 of 9 patients. Marked tumor volume reduction was obtained with the neuroendoscopic procedure alone at 6 months, 1 year, and 2 years. One recurrent case showed multilobulated cysts, and a second surgery was required 1 year after the treatment. Clinical symptoms such as headache and visual disruption were rapidly alleviated after the neuroendoscopic procedure. No new visual disturbances, endocrinopathy, or hypothalamic dysfunction was observed during follow up.@*Conclusions@#Stereotactic radiotherapy for cystic craniopharyngioma after endoscopic fenestration can effectively control the tumor for a long period of time, improve the clinical symptoms and avoid endocrine diseases.
ABSTRACT
Objective To determine the effect of a motor-specific neurotrophic factor,glial-derived neurotrophic factor (GDNF) on motor nerve regeneration.Methods We used a nerve conduit filled with a fibrin-based delivery system that provided controlled release of GDNF during nerve regeneration.The motor branch of the rat femoral nerve was used to assess motor nerve regeneration across a 5-mm gap.Four experimental groups (n =5) were evaluated.These included GDNF with the fibrin-based delivery system (GDNFDS group),fibrin alone(fibrin group),empty conduit (negative control group),and nerve isograft (positive control group).Nerves were harvested at 5 weeks for analysis by histomorphometry and electron microscopy.Results At 5 mm distal to the conduit or isografts,the GDNF-DS group was not significantly different from the nerve isograft group in the following histomorphometric measures:total nerve fibers,percentage of neural tissue,and nerve density.The number of nerve fibers (respectively:1 744 ± 274,1 481 ± 288)and the percentage of nerve tissue [(14.2 ± 3.9) ％,(11.0 ± 2.2) ％] in theisograft group and the GDNFDS group were significantly higher than that in the fibrin group and the empty conduit group [(respectively:538 ± 93,535 ± 96) and the percentage of nerve tissue respectively:(4.3 ± 1.6) ％,(3.7 ± 0.9) ％].There were no differences in fiber width among all groups.By electron microscopy,the GDNF-DS and isograft groups also demonstrated more organized nerve architecture than the fibrin alone and empty conduit groups.Conclusions The delivery of GDNF from the fibrin-based delivery system promotes motor nerve regeneration at a level similar to an isograft in the femoral motor nerve model.This study gives insight into the potential beneficial role of GDNF in the treatment of motor nerve injuries.
ABSTRACT
Objective To explore the long-term effect of neuroendoscopy followed by radiotherapy on cystic craniopharyngiomas.Methods Cystic craniopharyngiomas in 9 patients were treated with neuroendoscopic cyst aspiration and fenestration,followed by fractionated stereotactic radiotherapy (FSRT).The neuroendoscopic procedure focused on widening of cyst fenestration and extensive irrigation of the cyst contents.The collimator of FSRT ranged from 2.5 cm to 3.0 cm,and the target volume 1.1-43.8 cm3,dose per fraction 1.8 Gy,total dose 50.4 Gy.Results The median follow-up period was 72.9 months.Tumor control was achieved in 8 of 9 patients.Marked tumor volume reduction was obtained with the neuroendoscopic procedure alone at 6 months,1 year,and 2 years.One recurrent case showed multilobulated cysts,and a second surgery was required 1 year after the treatment.Clinical symptoms such as headache and visual disruption were rapidly alleviated after the neuroendoscopic procedure.No new visual disturbances,endocrinopathy,or hypothalamic dysfunction was observed during follow up.Conclusions Stereotactic radiotherapy for cystic craniopharyngioma after endoscopic fenestration can effectively control the tumor for a long period of time,improve the clinical symptoms and avoid endocrine diseases.
ABSTRACT
Objective@#To determine the effect of a motor-specific neurotrophic factor, glial-derived neurotrophic factor (GDNF) on motor nerve regeneration.@*Methods@#We used a nerve conduit filled with a fibrin-based delivery system that provided controlled release of GDNF during nerve regeneration. The motor branch of the rat femoral nerve was used to assess motor nerve regeneration across a 5-mm gap. Four experimental groups (n=5) were evaluated. These included GDNF with the fibrin-based delivery system (GDNF-DS group), fibrin alone(fibrin group), empty conduit (negative control group), and nerve isograft (positive control group). Nerves were harvested at 5 weeks for analysis by histomorphometry and electron microscopy.@*Results@#At 5 mm distal to the conduit or isografts, the GDNF-DS group was not significantly different from the nerve isograft group in the following histomorphometric measures: total nerve fibers, percentage of neural tissue, and nerve density. The number of nerve fibers (respectively: 1 744±274 , 1 481±288) and the percentage of nerve tissue [(14.2±3.9)%, (11.0±2.2)%] in theisograft group and the GDNF-DS group were significantly higher than that in the fibrin group and the empty conduit group [(respectively: 538±93, 535±96) and the percentage of nerve tissue respectively: (4.3±1.6)%, (3.7±0.9)%]. There were no differences in fiber width among all groups. By electron microscopy, the GDNF-DS and isograft groups also demonstrated more organized nerve architecture than the fibrin alone and empty conduit groups.@*Conclusions@#The delivery of GDNF from the fibrin-based delivery system promotes motor nerve regeneration at a level similar to an isograft in the femoral motor nerve model. This study gives insight into the potential beneficial role of GDNF in the treatment of motor nerve injuries.
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Objective To investigate the clinical features of bilateral medial medullary infarction (BMMI)in elderly patients.Methods Clinical and imaging data of 8 elderly BMMI patients with different morphology on diffusion-weighted magnetic resonance imaging (DWI-MR) were retrospectively analyzed.All patients were diagnosed by MRI,while 4 patients received CTA and vascular ultrasound testing,and the other 4 patients received vascular ultrasound testing.Results All 8 cases(100.0％) had acute-onset BMMI.Patients showed varying degrees of acroparalysis(7/8,87.5 ％),dizziness (5/8,62.5 ％),dysarthria(6/8,80.0 ％),dysphagia(3/8,37.5 ％),deep or superficial sensory dysfunction(5/8,62.5 ％),consciousness disorders (2/8,25.0 ％),dyspnea (2/8,25.0 ％),and tinnitus(1/8,12.5 ％).Lesions in most patients were located in the upper part of medulla oblongata(7/8,87.5 ％).In the transverse direction of DWI,the lesions as the inverted V shape were seen in 3 cases (37.5％),the V shape(12.5％)in 1 case,the Y shape(37.5％)in 3 cases,and the heart shape(12.5％) in 1 case.All 8 patients were complicated with posterior cerebral artery stenosis or occlusion,of whom patients with heart-or Y-shaped lesions showed progressive exacerbation.After treatment,4 cases (50.0 ％) recovered,3 cases (37.5 ％) improved,and 1 case (12.5 ％) unrecovered before discharge from the hospital.Conclusions Most elderly BMMI patients have concurrent posterior circulation artery stenosis,and patients with heart-or Y-shaped lesions on MR-DWI show rapid progression and have a poor prognosis.Cranial examination with MR-DWI is helpful for early clinical diagnosis of BMMI,prediction of disease progression and effective prevention of complications.