Demonstration of the Formation of a Selenocysteine Selenenic Acid through Hydrolysis of a Selenocysteine Selenenyl Iodide Utilizing a Protective Molecular Cradle.

Selenocysteine selenenic acids (Sec-SeOHs) and selenocysteine selenenyl iodides (Sec-SeIs) have long been recognized as crucial intermediates in the catalytic cycle of glutathione peroxidase (GPx) and iodothyronine deiodinase (Dio), respectively. However, the observation of these reactive species remained elusive until our recent study, where we successfully stabilized Sec-SeOHs and Sec-SeIs using a protective molecular cradle. Here, we report the first demonstration of the chemical transformation from a Sec-SeI to a Sec-SeOH through alkaline hydrolysis. A stable Sec-SeI derived from a selenocysteine methyl ester was synthesized using the protective cradle, and its structure was determined by crystallographic analysis. The alkaline hydrolysis of the Sec-SeI at -50 °C yielded the corresponding Sec-SeOH in an 89% NMR yield, the formation of which was further confirmed by its reaction with dimedone. The facile and nearly quantitative conversion of the Sec-SeI to the Sec-SeOH not only validates the potential involvement of this process in the catalytic mechanism of Dio, but also highlights its utility as a method for producing a Sec-SeOH.

Fluid-Attenuated Inversion Recovery May Serve As a Tissue Clock in Patients Treated With Endovascular Thrombectomy.

Background and Purpose: We investigated whether the signal change on fluid-attenuated inversion recovery (FLAIR) can serve as a tissue clock that predicts the clinical outcome after endovascular thrombectomy (EVT), independently of the onset-to-admission time. Methods: Consecutive patients with acute stroke treated with EVT between September 2014 and December 2018 were enrolled. Based on the parenchymal signal change on FLAIR, patients were classified into FLAIR-negative and FLAIR-positive groups. The clinical characteristics, imaging findings, EVT parameters, and the intracranial hemorrhage defined as Heidelberg Bleeding Classification ≥1c hemorrhage (parenchymal hemorrhage, intraventricular hemorrhage, subarachnoid hemorrhage, and/or subdural hemorrhage) were compared between the 2 groups. A modified Rankin Scale score 0 to 1 at 3 months was considered to represent a good outcome. Results: Of the 227 patients with EVT during the study period, 140 patients (62%) were classified into the FLAIR-negative group and 87 (38%) were classified into the FLAIR-positive group. In the FLAIR-negative group, the patients were older (P=0.011), the onset-to-image time was shorter (P<0.001), the frequency of cardioembolic stroke was higher (P=0.006), and the rate of intravenous thrombolysis was higher (P<0.001) in comparison to the FLAIR-positive group. Although the rate of complete recanalization after EVT did not differ between the 2 groups (P=0.173), the frequency of both any-intracranial hemorrhage and Heidelberg Bleeding Classification ≥1c hemorrhage were higher in the FLAIR-positive group (P=0.004 and 0.011). At 3 months, the percentage of patients with a good outcome (FLAIR-negative, 41%; FLAIR-positive, 27%) was significantly related to the FLAIR signal change (P=0.047), while the onset-to-image time was not significant (P=0.271). A multivariate regression analysis showed that a FLAIR-negative status was independently associated with a good outcome (odds ratio, 2.10 [95% CI, 1.02­4.31], P=0.044). Conclusions: A FLAIR-negative status may predict the clinical outcome more accurately than the onset-to-admission time, which may support the role of FLAIR as a tissue clock.

Modeling the Catalytic Cycle of Glutathione Peroxidase by Nuclear Magnetic Resonance Spectroscopic Analysis of Selenocysteine Selenenic Acids.

Although selenocysteine selenenic acids (Sec-SeOHs) have been recognized as key intermediates in the catalytic cycle of glutathione peroxidase (GPx), examples of the direct observation of Sec-SeOH in either protein or small-molecule systems have remained elusive so far, mostly due to their instability. Here, we report the first direct spectroscopic (1H and 77Se NMR) evidence for the formation of Sec-SeOH in small-molecule selenocysteine and selenopeptide model systems with a cradle-type protective group. The catalytic cycle of GPx was investigated using NMR-observable Sec-SeOH models. All the hitherto proposed chemical processes, i.e., not only those of the canonical catalytic cycle but also those involved in the bypass mechanism, including the intramolecular cyclization of Sec-SeOH to the corresponding five-membered ring selenenyl amide, were examined in a stepwise manner.

Synthesis of a Stable Primary-Alkyl-Substituted Selenenyl Iodide and Its Hydrolytic Conversion to the Corresponding Selenenic Acid.

A primary-alkyl-substituted selenenyl iodide was successfully synthesized through oxidative iodination of a selenol with N-iodosuccinimide by taking advantage of a cavity-shaped steric protection group. The selenenyl iodide exhibited high thermal stability and remained unchanged upon heating at 100 °C for 3 h in [D8]toluene. The selenenyl iodide was reduced to the corresponding selenol by treatment with dithiothreitol. Hydrolysis of the selenenyl iodide under alkaline conditions afforded the corresponding selenenic acid almost quantitatively, corroborating the chemical validity of the recent proposal that hydrolysis of a selenenyl iodide to a selenenic acid is potentially involved in the catalytic mechanism of an iodothyronine deiodinase.

Hyperglycemia and Outcomes in Patients with Successful Reperfusion by Mechanical Thrombectomy.

Background This study examined whether or not hyperglycemia on admission is associated with poor outcomes in patients with successful reperfusion by mechanical thrombectomy (MT). Methods Consecutive patients with acute anterior circulation stroke and large-vessel occlusion treated with MT were evaluated. Hyperglycemia was defined as a blood glucose level of >140 mg/dL on admission. Successful reperfusion was defined as Thrombolysis in Cerebral Infarction of grade 2b or 3. A poor clinical outcome 90 days after the onset was defined as a modified Rankin Scale score of 4-6. We compared characteristics, including outcomes, between the normoglycemic (≤140 mg/dL) and hyperglycemic groups. In addition, the association between hyperglycemia and outcomes was evaluated in patients with successful reperfusion using MT. Results The participants comprised 407 patients (median age, 76.5 years old; 58.0% men; median NIHSS (National Institutes of Health Stroke Scale) score, 17). The site of occlusion was the ICA (Internal Carotid Artery) in 119 patients (29.2%) and the M1 in 178 patients (43.7%). Normoglycemia, hyperglycemia, successful reperfusion, and poor outcomes were found in 138 (33.9%), 269 (66.1%), 320 (78.6%), and 141 (34.4%) patients, respectively. Poor outcomes were more frequent in hyperglycemic patients (61.6%) than in normoglycemic patients (43.9%, P=0.001). Among patients with successful reperfusion, poor outcomes were more frequent in hyperglycemic patients (57.8%) than in normoglycemic patients (37.9%; P<0.001). In patients with successful reperfusion, a multivariate regression analysis identified hyperglycemia as a factor associated with poor outcomes (odds ratio, 2.151; confidence interval, 1.166-3.970; P=0.014). Conclusions Among all patients, hyperglycemia on admission was associated with a poor outcome in those treated with MT. Regarding the presence of successful reperfusion by MT, patients with successful reperfusion had such effects.

Pathological Findings of Embolus Retrieved by Mechanical Thrombectomy in Cerebral Embolism with Libman-Sacks Endocarditis: A Report of Two Cases.

Libman-Sacks endocarditis is an important cause of embolic stroke in systemic lupus erythematosus, although the detailed pathogenesis of stroke remains unclear. We herein report two cases of stroke with Libman-Sacks endocarditis in which the emboli were retrieved by mechanical thrombectomy. The embolus consisted of eosinophilic homogeneous acellular structures, whereas fibrin-platelet thrombi were hardly observed in the embolus. Immunohistochemistry showed immunoglobulin deposits in the embolus, suggesting that immunological mechanisms were involved in the growth of the embolus. A pathological analysis of the embolus retrieved by mechanical thrombectomy provided useful information on the etiology, leading to optimal treatment.

Repeated Ischemic Stroke due to in situ Thrombus at the Middle Cerebral Artery in a Patient with Essential Thrombocythemia.

Essential thrombocythemia (ET) is a myeloproliferative neoplasm that is a rare cause of ischemic stroke. We herein report a 70-year-old man with JAK2 V617F mutation-positive ET who experienced ischemic stroke twice in 1 month due to transient stenosis. In both events, transient stenosis formed at the same curvature of the right middle cerebral artery, and the thrombus disappeared with the initiation of antiplatelet agents. The formation of in situ thrombus at the curvature of the intracranial vessels may be a unique characteristic of JAK2 V617F mutation-positive ET patients.

Association between Mobility of Residual Left Atrial Thrombus and Stroke Severity in Patients with Nonvalvular Atrial Fibrillation.

BACKGROUND: The differences in the characteristics of ischemic stroke associated with a mobile versus nonmobile residual left atrial thrombus (LAT) are unclear. We investigated whether the mobility of an LAT detected by transthoracic echocardiography is associated with the clinical features of stroke. METHODS: This study included 20 consecutive patients with nonvalvular atrial fibrillation who were admitted to our hospital for treatment of acute ischemic stroke and then found to have an LAT on transthoracic echocardiography. The patients were divided into two groups: those with a mobile LAT (Group M) and those with a nonmobile LAT (Group N). The clinical, neuroradiological, and echocardiographic variables were assessed. RESULTS: The LAT was mobile in 11 patients (Group M) and nonmobile in nine patients (Group N). The median National Institutes of Health Stroke Scale score on admission was higher in Group M than N (17 vs. 7, respectively; p=0.196). Four patients in Group M and one in Group N developed in-hospital stroke recurrence (36% vs. 11%, respectively; p=0.319). The prevalence of large vessel occlusion (15 events in Group M and 10 events in Group N, including in-hospital recurrent events) was significantly higher in Group M than N (73% vs. 30%, respectively; p=0.049), which seemed to lead to poorer functional outcomes in Group M than N (ratio of modified Rankin scale score of 0-2 at discharge: 18% vs. 44%, respectively; p=0.336). CONCLUSIONS: The mobility of LAT may affect stroke severity in patients with nonvalvular atrial fibrillation.

Mechanical Thrombectomy Treatment More than 16 h after Last Known Well for Patients with Large Vessel Occlusion.

INTRODUCTION: Mechanical thrombectomy (MT) has been reported to be effective within 24 h after last known well (LKW) by the DAWN (DWI or CTP Assessment with Clinical Mismatch in the Triage of Wake-Up and Late Presenting Strokes Undergoing Neurointervention with Trevo) trial and within 16 h after LKW by the DEFUSE-3 (Endovascular Therapy Following Imaging Evaluation for Ischemic Stroke 3) trial. However, there have been few reports of MT more than 16 h after LKW, and the efficacy and safety of MT more than 24 h after LKW have not yet been demonstrated. We evaluated the efficacy and safety of MT more than 16 h after LKW. METHODS: Using data from the Nippon Medical School Hospital MT registry from April 2011 to August 2022, consecutive patients with anterior circulation large vessel occlusion (LVO) and prehospital modified Rankin scale (mRS) scores of 0-3 were enrolled. Patients were classified into the following three groups: early group (LKW <6 h), middle group (LKW 6-16 h), and late group (LKW >16 h). The clinical characteristics and outcomes were compared among these three groups. RESULTS: Among 778 patients in the MT registry, 624 were enrolled. The early group included 432 patients, the middle group included 123 patients, and the late group included 69 patients. The patients had a median age of 77 years (interquartile range, 68-83), and 359 were male (57.5%). The median prehospital mRS score was 1 (interquartile range, 1-1), median National Institutes of Health Stroke Scale score on admission was 17 (interquartile range, 10-23), and median Alberta Stroke Program Early CT Score was 10 (interquartile range, 8-10). Regarding safety and efficacy, the proportions of cases with successful reperfusion (modified Thrombolysis in Cerebral Infarction score of 2b-3; 85.4% vs. 92.7% vs. 88.7%; p = 0.47), symptomatic intracranial haemorrhage (6.4% vs. 5.7% vs. 7.2%; p = 0.99), mRS score ≤3 at 90 days (52.0% vs. 60.2% vs. 44.9%; p = 0.11), and mRS score of 6 at 90 days (11.3% vs. 10.6 vs. 8.7%; p = 0.37) were not significantly different between the three groups. CONCLUSION: Patients who received MT more than 16 h after LKW experienced the same safety and efficacy as those who received MT at 0-16 h after LKW. MT more than 16 h after LKW may be safe and effective for stroke patients with LVO.

[A case of neurogenic pulmonary edema due to left internal carotid artery occlusion].

A 79-year-old woman developed consciousness disturbance, left eye deviation, right hemiplegia and aphasia with hypoxemia. Chest X-ray showed bilateral pulmonary edema. MRI revealed the left internal carotid artery occlusion and entire left middle cerebral artery infarct including insular cortex. We performed mechanical thrombectomy therapy and TICI3 recanalization was obtained. During operation, the respiratory condition deteriorated and the ventilator was started after mechanical thrombectomy therapy. Chest X-ray showed butterfly shadow, which indicated pulmonary edema. Pulmonary edema improved on the 2nd day of onset, and disappeared on the 3rd day. There was no heart diseases such as Takotsubo myocardiopathy, acute cardiac failure and cardiomyopathy on echocardiography and electrocardiography. Therefore, we diagnosed her as having neurogenic pulmonary edema due to cerebral infarction including insular cortex. We consider that left insular cortex infarction was a trigger of neurogenic pulmonary edema. If hypoxemia associated with infarction including the insular cortex, neurogenic pulmonary edema should be considered for medical treatment.

ß-Thujaplicin Enhances TRAIL-Induced Apoptosis via the Dual Effects of XIAP Inhibition and Degradation in NCI-H460 Human Lung Cancer Cells.

Background: ß-thujaplicin, a natural tropolone derivative, has anticancer effects on various cancer cells via apoptosis. However, the apoptosis regulatory proteins involved in this process have yet to be revealed. Methods: Trypan blue staining, a WST-8 assay, and a caspase-3/7 activity assay were used to investigate whether ß-thujaplicin sensitizes cancer cells to TNF-related apoptosis-inducing ligand (TRAIL)-mediated apoptosis. Additionally, western blotting was performed to clarify the effects of ß-thujaplicin on X-linked inhibitor of apoptosis protein (XIAP) in NCI-H460 cells and a fluorescence polarization binding assay was used to evaluate the binding-inhibitory activity of ß-thujaplicin against XIAP-BIR3. Results: ß- and γ-thujaplicins decreased the viability of NCI-H460 cells in a dose-dependent manner; they also sensitized the cells to TRAIL-induced cell growth inhibition and apoptosis. ß-thujaplicin significantly potentiated the apoptosis induction effect of TRAIL on NCI-H460 cells, which was accompanied by enhanced caspase-3/7 activity. Interestingly, ß-thujaplicin treatment in NCI-H460 cells decreased XIAP levels. Furthermore, ß-thujaplicin was able to bind XIAP-BIR3 at the Smac binding site. Conclusions: These findings indicate that ß-thujaplicin could enhance TRAIL-induced apoptosis in NCI-H460 cells via XIAP inhibition and degradation. Thus, the tropolone scaffold may be useful for designing novel nonpeptidic small-molecule inhibitors of XIAP and developing new types of anticancer drugs.

Thrombectomy for Upper Extremity Artery Occlusion with Major Cerebral Artery Occlusion Using Mechanical Thrombectomy Devices for Acute Ischemic Stroke.

Objective: We report two cases of thrombectomy for upper extremity artery occlusion with major cerebral artery occlusion using mechanical thrombectomy devices for acute ischemic stroke. Case Presentations: Case 1 was a 79-year-old woman admitted for left internal carotid artery occlusion and left upper extremity artery occlusion. Case 2 was an 87-year-old woman admitted for left middle cerebral artery occlusion and bilateral upper extremity artery occlusion. After performing mechanical thrombectomy for the cerebral artery, we achieved good recanalization of the brachial artery using the same devices in Case 1 and Case 2. Conclusions: Thrombectomy using acute ischemic stroke mechanical thrombectomy devices for upper extremity artery occlusion is useful for recanalization.

Mutations in the testis-specific enhancer of SOX9 in the SRY independent sex-determining mechanism in the genus Tokudaia.

SRY (sex-determining region Y) is widely conserved in eutherian mammals as a sex-determining gene located on the Y chromosome. SRY proteins bind to the testis-specific enhancer of SOX9 (TES) with SF1 to upregulate SOX9 expression in undifferentiated gonads of XY embryos of humans and mice. The core region within TES, named TESCO, is an important enhancer for mammalian sex determination. We show that TESCO of the genus Tokudaia lost enhancer activity caused by mutations in its SRY and SF1 binding sites. Two species of Tokudaia do not have the Y chromosome or SRY, and one species has multiple SRYs located on the neo-Y chromosome consisting of the Y fused with an autosome. The sequence of Tokudaia TESCO exhibited more than 83% identity with mouse TESCO, however, nucleotide substitution(s) were found in two out of three SRY binding sites and in five out of six SF1 binding sites. TESCO of all species showed low enhancer activity in cells co-transfected with SRY and SF1, and SOX9 and SF1 in reporter gene assays. Mutated TESCO, in which nucleotide substitutions found in SRY and SF1 binding sites were replaced with mouse sequence, recovered the activity. Furthermore, SRYs of the SRY-positive species could not activate the mutated TESCO or mouse TESCO, suggesting that SRYs lost function as a sex-determining gene any more. Our results indicate that the SRY dependent sex-determining mechanism was lost in a common ancestor of the genus Tokudaia caused by nucleotide substitutions in SRY and SF1 binding sites after emergence of a new sex-determining gene. We present the first evidence for an intermediate stage of the switchover from SRY to a new sex-determining gene in the evolution of mammalian sex-determining mechanism.