Recent Advances in Cell-Based Therapies for Ischemic Stroke.

Stroke is the most prevalent cardiovascular disease worldwide, and is still one of the leading causes of death and disability. Stem cell-based therapy is actively being investigated as a new potential treatment for certain neurological disorders, including stroke. Various types of cells, including bone marrow mononuclear cells, bone marrow mesenchymal stem cells, dental pulp stem cells, neural stem cells, inducible pluripotent stem cells, and genetically modified stem cells have been found to improve neurological outcomes in animal models of stroke, and there are some ongoing clinical trials assessing their efficacy in humans. In this review, we aim to summarize the recent advances in cell-based therapies to treat stroke.

Reversible Hydrogen Releasing and Fixing with Poly(Vinylfluorenol) through a Mild Ir-Catalyzed Dehydrogenation and Electrochemical Hydrogenation.

The radical polymerization of 2-vinylfluorenol, an alcohol derivative of vinylfluorene, gives poly(vinylfluorenol), which quantitatively releases hydrogen gas (≈110 mL per gram polymer at standard temperature and pressure) by simply warming at 100 °C with an iridium catalyst. A high population of fluorenol units in the polymer accomplishes a large formula-weight-based theoretical hydrogen density (1.0 wt%). The dehydrogenated ketone derivative, poly(vinylfluorenone), exhibits reversible negative-charge storage with a high density of 260 mAh g-1 . The electrolytically reduced poly(vinylfluorenone) is momentarily hydrogenated in the presence of an electrolyte with water as the hydrogen source to be converted to the original poly(vinylfluorenol). The formed poly(vinylfluorenol) almost quantitatively evolves hydrogen gas similar to the starting poly(vinylfluorenol). Both hydrogen and charge storage with the organic fluorenol/fluorenone polymer suggest a new type of energy-storage configuration.

Multicenter Prospective Analysis of Stroke Patients Taking Oral Anticoagulants: The PASTA Registry - Study Design and Characteristics.

OBJECTIVES: The management of atrial fibrillation and deep venous thrombosis has evolved with the development of direct oral anticoagulants (DOAC), and oral anticoagulant (OAC) might influence the development or clinical course in both ischemic and hemorrhagic stroke. However, detailed data on the differences between the effects of the prior prescription of warfarin and DOAC on the clinical characteristics, neuroradiologic findings, and outcome of stroke are limited. DESIGN: The prospective analysis of stroke patients taking anticoagulants (PASTA) registry study is an observational, multicenter, prospective registry of stroke (ischemic stroke, transient ischemic attack, and intracerebral hemorrhage) patients receiving OAC in Japan. This study is designed to collect data on clinical background characteristics, drug adherence, drug dosage, neurological severity at admission and discharge, infarct or hematoma size, acute therapy including recanalization therapy or reverse drug therapy, and timing of OAC re-initiation. Patient enrollment started in April 2016 and the target patient number is 1000 patients. CONCLUSIONS: The PASTA prospective registry should identify the status of stroke patients taking OAC in the current clinical practice in Japan.

Characteristics of Ischemic Versus Hemorrhagic Stroke in Patients Receiving Oral Anticoagulants: Results of the PASTA Study.

Objective Limited data exist regarding the comparative detailed clinical characteristics of patients with ischemic stroke (IS)/transient ischemic attack (TIA) and intracerebral hemorrhage (ICH) receiving oral anticoagulants (OACs). Methods The prospective analysis of stroke patients taking oral anticoagulants (PASTA) registry, a multicenter registry of 1,043 stroke patients receiving OACs [vitamin K antagonists (VKAs) or non-vitamin K antagonist oral anticoagulant (NOACs)] across 25 medical institutions throughout Japan, was used. Univariate and multivariable analyses were used to analyze differences in clinical characteristics between IS/TIA and ICH patients with atrial fibrillation (AF) who were registered in the PASTA registry. Results There was no significant differences in cardiovascular risk factors, such as hypertension, diabetes mellitus, dyslipidemia, smoking, or alcohol consumption (all p>0.05), between IS/TIA and ICH among both NOAC and VKA users. Cerebral microbleeds (CMBs) [odds ratio (OR), 4.77; p<0.0001] were independently associated with ICH, and high brain natriuretic peptide/N-terminal pro B-type natriuretic peptide levels (OR, 1.89; p=0.0390) were independently associated with IS/TIA among NOAC users. A history of ICH (OR, 13.59; p=0.0279) and the high prothrombin time-international normalized ratio (PT-INR) (OR, 1.17; p<0.0001) were independently associated with ICH, and a history of IS/TIA (OR, 3.37; 95% CI, 1.34-8.49; p=0.0101) and high D-dimer levels (OR, 2.47; 95% CI, 1.05-5.82; p=0.0377) were independently associated with IS/TIA among VKA users. Conclusion The presence of CMBs, a history of stroke, natriuretic peptide and D-dimer levels, and PT-INR may be useful for risk stratification of either IS/TIA or ICH development in patients with AF receiving OACs.

Mild Encephalitis/Encephalopathy with a Reversible Splenial Lesion in an Adult with Cerebellar Ataxia: A Case Report.

Mild encephalitis/encephalopathy with a reversible splenial lesion (MERS) is a clinicoradiological syndrome characterized by transient mild encephalopathy and magnetic resonance imaging (MRI) findings of a reversible lesion in the splenium of the corpus callosum (SCC). Patients with MERS generally present with central nervous system symptoms such as consciousness disturbance, headache, and seizure; adult-onset MERS with cerebellar ataxia is rare. A 53-year-old man was admitted to our hospital with fever of 1 week's duration, headache, neck stiffness, and gait disturbance. Neurological examination revealed bilateral intention tremor (predominantly affecting the right hand) and gait ataxia. Diffusion-weighted brain MRI showed a focal hyperintense lesion in the SCC. Cerebrospinal fluid analysis revealed elevated levels of mononuclear cells and proteins. Brain imaging with 123I-iofetamine single-photon emission computed tomography showed reduced cerebral blood flow in the left thalamus and right cerebellum. Several diseases, including cerebellar stroke and acute cerebellitis, develop as comorbidities in patients with acute cerebellar ataxia. This case suggests that MERS should be suspected in adults with cerebellar ataxia.

Feasibility of Human Neural Stem Cell Transplantation for the Treatment of Acute Subdural Hematoma in a Rat Model: A Pilot Study.

Human neural stem cells (hNSCs) transplantation in several brain injury models has established their therapeutic potential. However, the feasibility of hNSCs transplantation is still not clear for acute subdural hematoma (ASDH) brain injury that needs external decompression. Thus, the aim of this pilot study was to test feasibility using a rat ASDH decompression model with two clinically relevant transplantation methods. Two different methods, in situ stereotactic injection and hNSC-embedded matrix seating on the brain surface, were attempted. Athymic rats were randomized to uninjured or ASDH groups (F344/NJcl-rnu/rnu, n = 7-10/group). Animals in injury group were subjected to ASDH, and received decompressive craniectomy and 1-week after decompression surgery were transplanted with green fluorescent protein (GFP)-transduced hNSCs using one of two approaches. Histopathological examinations at 4 and 8 weeks showed that the GFP-positive hNSCs survived in injured brain tissue, extended neurite-like projections resembling neural dendrites. The in situ transplantation group had greater engraftment of hNSCs than matrix embedding approach. Immunohistochemistry with doublecortin, NeuN, and GFAP at 8 weeks after transplantation showed that transplanted hNSCs remained as immature neurons and did not differentiate toward to glial cell lines. Motor function was assessed with rotarod, compared to control group (n = 10). The latency to fall from the rotarod in hNSC in situ transplanted rats was significantly higher than in control rats (median, 113 s in hNSC vs. 69 s in control, P = 0.02). This study first demonstrates the robust engraftment of in situ transplanted hNSCs in a clinically-relevant ASDH decompression rat model. Further preclinical studies with longer study duration are warranted to verify the effectiveness of hNSC transplantation in amelioration of TBI induced deficits.

Transplantation of human dental pulp stem cells ameliorates brain damage following acute cerebral ischemia.

AIMS: Numerous experimental studies have shown that cellular therapy, including human dental pulp stem cells (DPSCs), is an attractive strategy for ischemic brain injury. Herein, we examined the effects of intravenous DPSC administration after transient middle cerebral artery occlusion in rats. METHODS: Male Sprague-Dawley rats received a transient 90 min middle cerebral artery occlusion. DPSCs (1 × 106 cells) or vehicle were administered via the femoral vein at 0 h or 3 h after ischemia-reperfusion. PKH26, a red fluorescent cell linker, was used to track the transplanted cells in the brain. Infarct volume, neurological deficits, and immunological analyses were performed at 24 h and 72 h after reperfusion. RESULTS: PKH26-positive cells were observed more frequently in the ipsilateral than the contralateral hemisphere. DPSCs transplanted at 0 h after reperfusion significantly reduced infarct volume and reversed motor deficits at 24 h and 72 h recovery. DPSCs transplanted at 3 h after reperfusion also significantly reduced infarct volume and improved motor function compared with vehicle groups at 24 h and 72 h recovery. Further, DPSC transplantation significantly inhibited microglial activation and pro-inflammatory cytokine expression compared with controls at 72 h after reperfusion. Moreover, DPSCs attenuated neuronal degeneration in the cortical ischemic boundary area. CONCLUSIONS: Systemic delivery of human DPSCs after reperfusion reduced ischemic damage and improved functional recovery in a rodent ischemia model, with a clinically relevant therapeutic window. The neuroprotective action of DPSCs may relate to the modulation of neuroinflammation during the acute phase of stroke.

AMPA Receptor Antagonist Perampanel Ameliorates Post-Stroke Functional and Cognitive Impairments.

Perampanel (PER), a noncompetitive α-amino-3-hydroxy-5-methyl-4-isoxazole propionate receptor antagonist, clinically used for seizure control, has been reported to exert neuroprotective effects in experimental models of neurodegenerative diseases. However, few studies have investigated the therapeutic effects of PER in brain injury including stroke. Our aim was to investigate the neuroprotective potential of PER using a rat transient middle cerebral artery occlusion (MCAO) model. Sprague-Dawley rats underwent 90-min MCAO followed by intraperitoneal PER administration at a dose of 1.5 mg/kg. Infarct volumes, neurological deficits, and immunological analyses were performed at 7 days after MCAO. PER significantly reduced infarct volumes (p < 0.05) and improved motor function (p < 0.05) compared with vehicle. Immunological analysis showed that PER significantly inhibited microglial activation, pro-inflammatory cytokine expression, and oxidative stress compared with vehicle. Moreover, PER suppressed neurodegeneration in the cortical ischemic boundary zone, via downregulation of Bcl-2-associated x and upregulation of Bcl-extra-large with Akt activation. In addition, post-stroke secondary neuronal damage and cognitive impairments, using the Y-maze test, were assessed 30 days after MCAO. PER significantly improved spatial working memory, which was accompanied by hippocampal CA1 neuronal loss and cortical thinning, compared with vehicle. These results indicate that PER attenuates infarct volumes and motor function deficits possibly through its anti-inflammatory, antioxidant, and anti-apoptotic activities, mediated via activation of phosphatidylinositol 3-kinase (PI3K)/Akt pathways in the acute ischemic phase, and further ameliorates post-stroke cognitive impairments via the suppression of secondary neuronal damage in the chronic ischemic phase.

Impact of Dental Pulp Stem Cells Overexpressing Hepatocyte Growth Factor after Cerebral Ischemia/Reperfusion in Rats.

Hepatocyte growth factor (HGF) has neuroprotective effects against ischemia-induced injuries. Dental pulp stem cell (DPSC) transplantation attenuates tissue injury in the brain of rats with post-transient middle cerebral artery occlusion. We sought to determine whether DPSCs that overexpress HGF can enhance their therapeutic effects on brain damage post-ischemia/reperfusion injury. Treatment with DPSCs overexpressing HGF reduced infarct volumes compared to unmodified DPSC treatment at 3 and 7 days post-transient middle cerebral artery occlusion. The use of unmodified DPSCs and DPSCs overexpressing HGF was associated with improved motor function compared to that with administration of vehicle at 7 days post-transient middle cerebral artery occlusion. DPSCs overexpressing HGF significantly inhibited microglial activation and pro-inflammatory cytokine production along with suppression of neuronal degeneration. Post-reperfusion, DPSCs overexpressing HGF attenuated the decreases in tight junction proteins, maintained blood-brain barrier integrity, and increased microvessel density in peri-infarct areas. The administration of DPSCs overexpressing HGF during the acute phase of stroke increased their neuroprotective effects by modulating inflammation and blood-brain barrier permeability, thereby promoting improvements in post-ischemia/reperfusion brain injury.

Expectant management for abdominal pregnancy.

This is the first English language report describing the expectant management for abdominal pregnancy. The patient was a 31-year-old multiparous woman who was transferred to our hospital on suspicion of ectopic pregnancy. Her serum human chorionic gonadotropin was positive, and a poorly-vascularized mass measuring about 4 cm was visualized in the Douglas pouch by transvaginal ultrasonography, as well as by pelvic magnetic resonance imaging. Because the bilateral adnexa were apparently intact, she was diagnosed with abdominal pregnancy, and expectant management was commenced. Unexpectedly, the mass remained in situ for nearly 3 years after her serum human chorionic gonadotropin tested negative. Laparoscopic removal of the mass was finally required because of persistent defecation pain. This case illustrates that some abdominal pregnancies can be managed expectantly, as is the case with tubal pregnancies. During the expectant management, however, it should be considered that the abdominal pregnancy mass may persist for a longer period and cause moderate symptoms necessitating surgical removal.

Mesenchymal Stem Cells Overexpressing Interleukin-10 Promote Neuroprotection in Experimental Acute Ischemic Stroke.

Interleukin (IL)-10 is a contributing factor to neuroprotection of mesenchymal stem cell (MSC) transplantation after ischemic stroke. Our aim was to increase therapeutic effects by combining MSCs and ex vivo IL-10 gene transfer with an adeno-associated virus (AAV) vector using a rat transient middle cerebral artery occlusion (MCAO) model. Sprague-Dawley rats underwent 90 min MCAO followed by intravenous administration of MSCs alone or IL-10 gene-transferred MSCs (MSC/IL-10) at 0 or 3 hr after ischemia reperfusion. Infarct lesions, neurological deficits, and immunological analyses were performed within 7 days after MCAO. 0-hr transplantation of MSCs alone and MSC/IL-10 significantly reduced infarct volumes and improved motor function. Conversely, 3-hr transplantation of MSC/IL-10, but not MSCs alone, significantly reduced infarct volumes (p < 0.01) and improved motor function (p < 0.01) compared with vehicle groups at 72 hr and 7 days after MCAO. Immunological analysis showed that MSC/IL-10 transplantation significantly inhibits microglial activation and pro-inflammatory cytokine expression compared with MSCs alone. Moreover, overexpressing IL-10 suppressed neuronal degeneration and improved survival of engrafted MSCs in the ischemic hemisphere. These results suggest that overexpressing IL-10 enhances the neuroprotective effects of MSC transplantation by anti-inflammatory modulation and thereby supports neuronal survival during the acute ischemic phase.

Acute vertebral artery origin occlusion leading to basilar artery thrombosis successfully treated by angioplasty with stenting and thrombectomy.

Few reports have described the successful treatment of stroke caused by acute vertebral artery (VA) origin occlusion by endovascular surgery. We describe the case of a 68-year-old man who experienced stroke due to left acute VA origin occlusion. Cerebral angiography showed that the left VA was occluded at its origin, the right VA had hypoplastic and origin stenosis, and the basilar artery was occluded by a thrombus. The VA origin occlusion was initially passed through with a 0.035-inch guide wire. An angioplasty was performed, and a coronary stent was appropriately placed. The VA origin was successfully recanalized. A balloon-assisted guiding catheter was navigated through the stent and a thrombectomy was performed using the Penumbra system. The patient's symptoms gradually improved postoperatively. Balloon-assisted catheter guidance through a vertebral artery stent permitted a successful thrombectomy using the Penumbra system and may be useful for treating stroke due to VA origin occlusion.

Aortic arch atherosclerosis in ischaemic stroke of unknown origin affects prognosis.

BACKGROUND: Cerebral infarction of unknown origin at admission accounts for half of all cerebral infarction cases in some institutions. However, the factors associated with cerebral infarction prognosis have not been sufficiently examined. Here, we investigated whether aortic arch plaques (AAPs) on transoesophageal echocardiography (TOE) were associated with the prognosis of cerebral infarction of unknown origin at admission. METHODS: Of 571 patients who were hospitalised between June 2009 and September 2011, 149 (age: 67 ± 14 years; 95 men) with cerebral infarctions of unknown origin at admission underwent TOE and were enrolled in this study. We examined their clinical characteristics, the incidence of intermittent atrial fibrillation detected on 24-hour electrocardiography, and the echographic findings of the carotid artery in the hospital. A poor prognostic outcome was defined as a modified Rankin Scale score of ≥3 after 90 days. RESULTS: In all, 110 patients (74%) showed good prognoses and 39 patients (26%) showed poor outcomes. A National Institutes of Health Stroke Scale score of >6 on admission [odds ratio (OR) = 6.77; 95% confidence interval (CI): 2.59-18.8; p < 0.001] and AAPs of ≥4 mm (OR = 2.75; 95% CI: 1.19-6.91; p = 0.024) showed significant associations with a poor prognosis of cerebral infarction of unknown origin at admission. CONCLUSIONS: Thick AAPs could be a factor in the prediction of a poor prognosis of cerebral infarction of unknown origin at admission. The establishment of international standards for aortogenic brain embolisms is required. Future prospective studies should examine cerebral infarctions of unknown origin.

Multiple vascular accidents including rupture of a sinus of valsalva aneurysm, a minor ischemic stroke and intracranial arterial anomaly in a patient with systemic congenital abnormalities: a case report.

A 39-year-old man with a history of rupture of a sinus of Valsalva aneurysm experienced an ischemic stroke. Although the patient presented left-sided hemiparesis for a week, no abnormal signals were indicated on diffusion-weighted imaging with repeated magnetic resonance scans. Carotid ultrasound and cerebral angiography were conducted, and they revealed hypoplasty of the left internal carotid artery with a low-lying carotid bifurcation at the level of the C6 vertebra. In addition, he was diagnosed with intellectual disabilities, evaluated by the Wechsler Adult Intelligence Scale-III, and congenital velopharyngeal insufficiency. We herein present the first report of a patient with cardio-cerebrovascular abnormalities, intellectual disabilities, and an otorhinolaryngological abnormality.

Synthesis of multiply deuterated 3- and 21-monosulfates of allo-tetrahydrocorticosteroids as internal standards for mass spectrometry.

The accurate analysis of trace components in complex biological matrices requires the use of reliable internal standards. For liquid chromatography/mass spectrometry analysis, the stable isotope-labeled analogues of the analyte molecules are the most appropriate internal standards. In this paper the synthesis of the 3- and 21-monosulfates of allo-tetrahydrocorticosteroids labeled with four or five deuterium atoms is described. The principal reactions used were (1) hydrogen-deuterium exchange reaction of active methylene groups adjacent to 3- and 11-oxo group of 17,20;20,21-bismethylenedioxy derivatives of 5α-3-ketosteroids and/or 5α-11-ketosteroids with NaOD in CH(3)OD followed by reduction with NaBD(4), (2) epimerization of the 3ß-hydroxy group into a 3α configuration, (3) sulfation of hydroxy groups at C-3 or C-21 in the resulting substrates with sulfur trioxide-trimethylamine complex, and (4) removal of 17,20;20,21-bismethylenedioxy groups with hydrogen fluoride in ethanol. Isotopic purity was found to be satisfactory by MS, and NMR properties of the new compounds were tabulated. The labeled compounds can be used as internal standards in liquid chromatography/mass spectrometry assays for clinical and biochemical studies.