Intra-arterial Thrombolysis for Central Retinal Artery Occlusion: Two Cases Report

Central retinal artery occlusion (CRAO) causes severe visual loss in affected eye and vision does not recover in more than 90% of the patients. It is believed that it occurs by occlusion of the central retinal artery with small emboli from atherosclerotic plaque of internal cerebral artery. Retina is a part of the brain, thus basically CRAO is corresponding to acute occlusion of intracerebral artery and retinal ischemia is to cerebral stroke. Therefore, intra-arterial thrombolysis (IAT) has been considered as a treatment method in CRAO. Recently, we treated 2 patients diagnosed as CRAO and could achieve complete recanalization on fundus fluorescein angiogram with IAT. Of them, one recovered visual acuity to 20/25. We report our 2 CRAO cases treated with IAT and discuss technical aspects for IAT and management of patient. To the best of our knowledge, this is the first Korean report of IAT for CRAO

Comparison of two automated CT perfusion software packages in patients with ischemic stroke presenting within 24 h of onset

BackgroundWe compared the ischemic core and hypoperfused tissue volumes estimated by RAPID and JLK-CTP, a newly developed automated computed tomography perfusion (CTP) analysis package. We also assessed agreement between ischemic core volumes by two software packages against early follow-up infarct volumes on diffusion-weighted images (DWI).MethodsThis retrospective study analyzed 327 patients admitted to a single stroke center in Korea from January 2021 to May 2023, who underwent CTP scans within 24 h of onset. The concordance correlation coefficient (ρ) and Bland–Altman plots were utilized to compare the volumes of ischemic core and hypoperfused tissue volumes between the software packages. Agreement with early (within 3 h from CTP) follow-up infarct volumes on diffusion-weighted imaging (n = 217) was also evaluated.ResultsThe mean age was 70.7 ± 13.0 and 137 (41.9%) were female. Ischemic core volumes by JLK-CTP and RAPID at the threshold of relative cerebral blood flow (rCBF) < 30% showed excellent agreement (ρ = 0.958 [95% CI, 0.949 to 0.966]). Excellent agreement was also observed for time to a maximum of the residue function (Tmax) > 6 s between JLK-CTP and RAPID (ρ = 0.835 [95% CI, 0.806 to 0.863]). Although early follow-up infarct volume showed substantial agreement in both packages (JLK-CTP, ρ = 0.751 and RAPID, ρ = 0.632), ischemic core volumes at the threshold of rCBF <30% tended to overestimate ischemic core volumes.ConclusionJLK-CTP and RAPID demonstrated remarkable concordance in estimating the volumes of the ischemic core and hypoperfused area based on CTP within 24 h from onset

Cloud Radio Random-Access Networks With Multi-Packet Reception Capability

Cloud Radio Access Network (C-RAN) refers to the virtualization of base station functionalities by means of cloud computing. With centralized processing at the cloud, the amount of hardware and infrastructure in a network can be reduced and it allows for operators to save expenses needed to deploy and maintain the network. Along with high spectral and energy efficiency, C-RAN becomes a key technology evolving to 5G network and it is also expected to play a critical role in the next generation of wireless network. In this paper, theoretical expressions are derived for throughput performance at Medium Access Control (MAC) layer with and without Cloud Radio Random-Access (CRRA). We first develop a CRRA protocol by accounting for the Multi-Packet Reception (MPR) capabilities afforded thanks to the deployment of C-RAN. We then analyze the throughput performance based on error exponent analysis. Numerical results show the performance advantages of C-RAN and verify theoretical expressions

Venous-predominant parenchymal arteriovenous malformation: a rare subtype with a venous drainage pattern mimicking developmental venous anomaly

OBJECT: Considerable confusion exists in the literature regarding the classification of cerebrovascular malformations and their clinical significance. One example is provided by the atypical developmental venous anomaly (DVA) with arteriovenous shunt, because it remains controversial whether these lesions should be classified as DVAs or as atypical cases of other subtypes of cerebrovascular malformations. The purpose of this study was to clarify the classification of these challenging vascular lesions in an effort to suggest an appropriate diagnosis and management strategy. METHODS: The authors present a series of 15 patients with intracranial vascular malformations that were angiographically classified as atypical DVAs with arteriovenous shunts. This type of vascular malformation shows a fine arterial blush without a distinct nidus and early filling of dilated medullary veins that drain these arterial components during the arterial phase on angiography. Those prominent medullary veins converge toward an enlarged main draining vein, which together form the caput medusae appearance of a typical DVA. RESULTS: Based on clinical, angiographic, surgical, and histological findings, the authors propose classifying these vascular malformations as a subtype of an arteriovenous malformation (AVM), rather than as a variant of DVA or as a combined vascular malformation. CONCLUSIONS: Correct recognition of this AVM subtype is required for its proper management, and its clinical behavior appears to follow that of a typical AVM. Gamma Knife radiosurgery appears to be a good alternative to resection, although long-term follow-up results require verification.This study was supported in part by a grant from the Korea Health 21 R&D Project, Ministry of Health & Welfare, Republic of Korea (Grant No. A06-0171-B51004-06N1-00040B)

Elevated Response to Type I IFN Enhances RANKL-Mediated Osteoclastogenesis in Usp18-Knockout Mice.

A balance between bone formation and bone resorption is critical for the maintenance of bone mass. In many pathological conditions, including chronic inflammation, uncontrolled activation of osteoclast differentiation often causes excessive bone resorption that results in osteoporosis. In this study, we identified the osteopenia phenotype of mice lacking Usp18 (also called Ubp43), which is a deISGylating enzyme and is known as a negative regulator of type I IFN signaling. The expression of Usp18 was induced in preosteoclasts upon receptor activator of NF-κB ligand (RANKL) treatment. In an in vitro osteoclast-differentiation assay, bone marrow macrophages from Usp18-deficient mice exhibited an enhanced differentiation to multinucleated cells, elevated activation of NFATc1, and an increased expression of osteoclast marker genes upon RANKL treatment. Furthermore, in vitro quantification of bone resorption revealed a great increase in osteoclastic activities in Usp18-deficient cells. Interestingly, proinflammatory cytokine genes, such as IP-10 (CXCL10), were highly expressed in Usp18-deficient bone marrow macrophages upon RANKL treatment compared with wild-type cells. In addition, serum cytokine levels, especially IP-10, were significantly high in Usp18-knockout mice. In sum, we suggest that, although type I IFN is known to restrict osteoclast differentiation, the exaggerated activation of the type I IFN response in Usp18-knockout mice causes an osteopenia phenotype in mice