Pathological Role of High Sugar in Mitochondrial Respiratory Chain Defect-Augmented Mitochondrial Stress.

According to many research groups, high glucose induces the overproduction of superoxide anions, with reactive oxygen species (ROS) generally being considered the link between high glucose levels and the toxicity seen at cellular levels. Respiratory complex anomalies can lead to the production of ROS. Calcium [Ca2+] at physiological levels serves as a second messenger in many physiological functions. Accordingly, mitochondrial calcium [Ca2+]m overload leads to ROS production, which can be lethal to the mitochondria through various mechanisms. F1F0-ATPase (ATP synthase or complex V) is the enzyme responsible for catalyzing the final step of oxidative phosphorylation. This is achieved by F1F0-ATPase coupling the translocation of protons in the mitochondrial intermembrane space and shuttling them to the mitochondrial matrix for ATP synthesis to take place. Mitochondrial complex V T8993G mutation specifically blocks the translocation of protons across the intermembrane space, thereby blocking ATP synthesis and, in turn, leading to Neuropathy, Ataxia, and Retinitis Pigmentosa (NARP) syndrome. This study seeks to explore the possibility of [Ca2+]m overload mediating the pathological roles of high glucose in defective respiratory chain-mediated mitochondrial stress. NARP cybrids are the in vitro experimental models of cells with F1FO-ATPase defects, with these cells harboring 98% of mtDNA T8993G mutations. Their counterparts, 143B osteosarcoma cell lines, are the parental cell lines used for comparison. We observed that NARP cells mediated and enhanced the death of cells (apoptosis) when incubated with hydrogen peroxide (H2O2) and high glucose, as depicted using the MTT assay of cell viability. Furthermore, using fluorescence probe-coupled laser scanning confocal imaging microscopy, NARP cells were found to significantly enable mitochondrial reactive oxygen species (mROS) formation and enhance the depolarization of the mitochondrial membrane potential (ΔΨm). Elucidating the mechanisms of sugar-enhanced toxicity on the mitochondria may, in the future, help to alleviate the symptoms of patients with NARP syndromes and other neurodegenerative diseases.

A disease-specific language representation model for cerebrovascular disease research.

BACKGROUND: Effectively utilizing disease-relevant text information from unstructured clinical notes for medical research presents many challenges. BERT (Bidirectional Encoder Representation from Transformers) related models such as BioBERT and ClinicalBERT, pre-trained on biomedical corpora and general clinical information, have shown promising performance in various biomedical language processing tasks. OBJECTIVES: This study aims to explore whether a BERT-based model pre-trained on disease-related clinical information can be more effective for cerebrovascular disease-relevant research. METHODS: This study proposed the StrokeBERT which was initialized from BioBERT and pre-trained on large-scale cerebrovascular disease related clinical text information. The pre-trained corpora contained 113,590 discharge notes, 105,743 radiology reports, and 38,199 neurological reports. Two real-world empirical clinical tasks were conducted to validate StrokeBERT's performance. The first task identified extracranial and intracranial artery stenosis from two independent sets of radiology angiography reports. The second task predicted the risk of recurrent ischemic stroke based on patients' first discharge information. RESULTS: In stenosis detection, StrokeBERT showed improved performance on targeted carotid arteries, with an average AUC compared to that of ClinicalBERT of 0.968 ± 0.021 and 0.956 ± 0.018, respectively. In recurrent ischemic stroke prediction, after 10-fold cross-validation on 1,700 discharge information, StrokeBERT presented better prediction ability (AUC±SD = 0.838 ± 0.017) than ClinicalBERT (AUC±SD = 0.808 ± 0.045). The attention scores of StrokeBERT showed better ability to detect and associate cerebrovascular disease related terms than current BERT based models. CONCLUSIONS: This study shows that a disease-specific BERT model improved the performance and accuracy of various disease-specific language processing tasks and can readily be fine-tuned to advance cerebrovascular disease research and further developed for clinical applications.

Impact of chronic kidney disease severity on causes of death after first-ever stroke: A population-based study using nationwide data linkage.

BACKGROUND: Stroke is prevalent in patients with chronic kidney disease (CKD) and is associated with high mortality, but the causes of death after stroke among different CKD stages are not well known. AIMS: We aimed to investigate whether the severity of CKD would impact on the causes of death after first-ever stroke. METHODS: This retrospective multicenter cohort study included stoke patients with CKD between 2007 and 2012. The cause of death and date of death were ascertained by linking the National Death Registry Database of Taiwan. Clinical outcomes, 1-month, and 1-year mortality rates, and major causes of death were compared according to five CKD stages (G1 to G5) in the ischemic and hemorrhagic stroke separately. RESULTS: Of these patients, 9,878 were first-ever ischemic stroke (IS) patients, and 1,387 were first-ever hemorrhagic stroke (HS) patients. Patients with CKD G5 had the highest one-year mortality rate with hazard ratio 5.28 [95%CI, 3.94-7.08] in IS and 3.03 [95%CI, 2.03-4.54] in HS when compared to G1 patients. Leading causes of one-year death after IS were stroke, cancer, and pneumonia in early (G1-3) CKD patients, while diabetes mellitus, CKD, and stroke itself contributed to the major mortality in CKD G5 patients. An inverse association between eGFR decrement and the proportion of deaths caused by stroke itself was observed in CKD G2-5 patients after IS. Stroke was the leading cause of one-year death among all CKD patients after HS. CONCLUSIONS: Asides from high mortality, late-stage CKD patients had different causes of death from early CKD patients after stroke. This study highlights the need to imply different treatment strategies in late-stage CKD post-stroke patients to improve their prognosis.

Comparison of long-term efficacy and safety between cilostazol and clopidogrel in chronic ischemic stroke: a nationwide cohort study.

BACKGROUND: Previous clinical trials showed a significant difference in efficacy and safety among antiplatelets in acute ischemic stroke (IS). The present study wished to compare the efficacy and safety head-to-head between cilostazol and clopidogrel in chronic IS. METHODS: This open prospective cohort study recruited chronic IS patients with an index hospitalization between 2001 and 2013 from Taiwan National Health Insurance Research Database. In the 504,191 hospitalized patients, patients who had missing information and history of atrial fibrillation or rheumatic heart disease, received mechanical valve replacement or anticoagulants, expired during the index hospitalization, received follow-up ⩽6 months, or had recurrent stroke within 6 months after index stroke were excluded. RESULTS: Among the 15,968 eligible patients, 502 patients who consistently received either cilostazol or clopidogrel from the 7th month after the index stroke were included for analysis after propensity score matching. The 3-year primary outcomes showed similar frequency of recurrent IS, all-cause mortality, and acute myocardial infarction (AMI), and similar frequency of intracerebral hemorrhage, gastrointestinal bleeding, and major bleeding between the cilostazol and clopidogrel groups. Subgroup analysis revealed that patients with a history of hypertension or gastrointestinal bleeding had a trend of having lower frequency of recurrent IS or major bleeding, respectively, in the cilostazol group. CONCLUSION: The present real-world study demonstrated no significant difference in efficacy and safety between cilostazol and clopidogrel in chronic IS. However, cilostazol might be better than clopidogrel in patients with a history of hypertension or gastrointestinal bleeding.

Risk Factors Associated with Outcomes of Recombinant Tissue Plasminogen Activator Therapy in Patients with Acute Ischemic Stroke.

Ischemic stroke is the most common type of stroke, and early interventional treatment is associated with favorable outcomes. In the guidelines, thrombolytic therapy using recombinant tissue-type plasminogen activator (rt-PA) is recommended for eligible patients with acute ischemic stroke. However, the risk of hemorrhagic complications limits the use of rt-PA, and the risk factors for poor treatment outcomes need to be identified. To identify the risk factors associated with in-hospital poor outcomes in patients treated with rt-PA, we analyzed the electronic medical records of patients who were diagnosed with acute ischemic stroke and treated for rt-PA at Chang Gung Memorial Hospitals from 2006 to 2016. In-hospital death, intensive care unit (ICU) stay, or prolonged hospitalization were defined as unfavorable treatment outcomes. Medical history variables and laboratory test results were considered variables of interest to determine risk factors. Among 643 eligible patients, 537 (83.5%) and 106 (16.5%) patients had favorable and poor outcomes, respectively. In the multivariable analysis, risk factors associated with poor outcomes were female gender, higher stroke severity index (SSI), higher serum glucose levels, lower mean corpuscular hemoglobin concentration (MCHC), lower platelet counts, and anemia. The risk factors found in this research could help us study the treatment strategy for ischemic stroke.

Low-dose versus standard-dose alteplase in acute ischemic stroke in Asian stroke registries: an individual patient data pooling study.

OBJECTIVE: To investigate the comparative efficacy and safety of the low-dose versus standard-dose alteplase using real-world acute stroke registry data from Asian countries. METHODS: Individual participant data were obtained from nine acute stroke registries from China, Japan, Philippines, Singapore, South Korea, and Taiwan between 2005 and 2018. Inverse probability of treatment weight was used to remove baseline imbalances between those receiving low-dose versus standard-dose alteplase. The primary outcome was death or disability defined by modified Rankin Scale scores of 2 to 6 at 90 days. Secondary outcomes were symptomatic intracerebral hemorrhage and death. Generalized linear mixed models with the individual registry as a random intercept were performed to determine associations of treatment with low-dose alteplase and outcomes. RESULTS: Of the 6250 patients (mean age 66 years, 36% women) included in these analyses, 1610 (24%) were treated with low-dose intravenous alteplase. Clinical outcomes for low-dose alteplase were not significantly different to those for standard-dose alteplase, adjusted odds ratios for death or disability: 1.00 (0.85-1.19) and symptomatic intracerebral hemorrhage 0.87 (0.63-1.19), except for lower death with borderline significance, 0.77 (0.59-1.01). CONCLUSIONS: The present analyses of real-world Asian acute stroke registry data suggest that low-dose intravenous alteplase has overall comparable efficacy for functional recovery and greater potential safety in terms of reduced mortality, to standard-dose alteplase for the treatment of acute ischemic stroke.

Protective stabilization of mitochondrial permeability transition and mitochondrial oxidation during mitochondrial Ca2+ stress by melatonin's cascade metabolites C3-OHM and AFMK in RBA1 astrocytes.

Cyclic 3-hydroxymelatonin (C3-OHM) and N1-acetyl-N2-formyl-5-methoxykynuramine (AFMK) are two major cascade metabolites of melatonin. We previously showed melatonin provides multiple levels of mitochondria-targeted protection beyond as a mitochondrial antioxidant during ionomycin-induced mitochondrial Ca2+ (mCa2+ ) stress in RBA1 astrocytes. Using noninvasive laser scanning fluorescence coupled time-lapse digital imaging microscopy, this study investigated whether C3-OHM and AFMK also provide mitochondrial levels of protection during ionomycin-induced mCa2+ stress in RBA1 astrocytes. Interestingly, precise temporal and spatial dynamic live mitochondrial images revealed that C3-OHM and AFMK prevented specifically mCa2+ -mediated mitochondrial reactive oxygen species (mROS) formation and hence mROS-mediated depolarization of mitochondrial membrane potential (△Ψm ) and permanent lethal opening of the MPT (p-MPT). The antioxidative effects of AFMK, however, were less potent than that of C3-OHM. Whether C3-OHM and AFMK targeted directly the MPT was investigated under a condition of "oxidation free-Ca2+ stress" using a classic antioxidant vitamin E to remove mCa2+ -mediated mROS stress and the potential antioxidative effects of C3-OHM and AFMK. Intriguingly, two compounds still effectively postponed "oxidation free-Ca2+ stress"-mediated depolarization of △Ψm and p-MPT. Measurements using a MPT pore-specific indicator Calcein further identified that C3-OHM and AFMK, rather than inhibiting, stabilized the MPT in its transient protective opening mode (t-MPT), a critical mechanism to reduce overloaded mROS and mCa2+ . These multiple layers of mitochondrial protection provided by C3-OHM and AFMK thus crucially allow melatonin to extend its metabolic cascades of mitochondrial protection during mROS- and mCa2+ -mediated MPT-associated apoptotic stresses and may provide therapeutic benefits against astrocyte-mediated neurodegeneration in the CNS.

Choices for long-term hypertensive control in patients after first-ever hemorrhagic stroke: a nationwide cohort study.

BACKGROUND: To compare the long-term clinical outcomes of different antihypertensive drugs in stable patients after acute hemorrhagic stroke (HS). METHODS: From January 2001 to December 2013, patients with first-ever primary HS were identified in the National Health Insurance Research Database, Taiwan. Patients with traumatic intracerebral hemorrhage and secondary HS were excluded. Those with first-ever HS were recruited and classified into three groups: (1) angiotensin-converting enzyme inhibitor/angiotensin receptor blocker (ACEI/ARB); (2) calcium channel blocker (CCB); and (3) other antihypertensive drugs (comparison) groups. Propensity score matching was used to balance the distribution of baseline characteristics, stroke severity, and medications between any two of the three groups. A validation study was performed using the databank of the Stroke Registry in Chang-Gung Healthcare System to reduce the bias. Primary outcomes were recurrent HS, ischemic stroke, any stroke, and all-cause mortality. RESULTS: Compared to the comparison group, the ACEI/ARB group [35.4% versus 39.3%; hazard ratio (HR), 0.84; 95% confidence interval (CI), 0.74-0.95] and CCB group (33.0% versus 41.9%; HR, 0.72; 95% CI, 0.64-0.81) had a lower risk of all-cause mortality during long-term follow up. The CCB group had a similar risk of all-cause mortality to the ACEI/ARB group. Risks of recurrent HS, ischemic stroke, or any stroke were not different between the study groups. CONCLUSIONS: Antihypertensive drug class could be important to long-term outcomes in HS patients in addition to the target control of blood pressure. Both ACEIs/ARBs and CCBs are associated with lower risks of all-cause mortality. Our results may be applied to inform future research on hypertensive control in HS patients.

Chest width, waist circumference, and thigh circumference are predictors of dementia.

OBJECTIVE: Few studies have investigated the relationship between specific body measures and dementia. METHODS: Three-dimensional anthropometric body surface scanning data containing 38 body measures were collected from 6831 participants from the health examination department of a medical center in Taiwan during 2000 to 2008, and 236 dementia cases were identified during the 10-year follow-up. A multiple Cox regression analysis was performed. RESULTS: Specific body measures, namely chest width (hazard ratio [HR] = 0.90; 95% confidence interval [CI] = 0.83-0.98), and right thigh circumference (HR = 0.93; 95% CI = 0.90-0.96), were protective predictors to dementia occurrence. Waist circumference (HR = 1.03; 95% CI = 1.02-1.05) was a risk factor in dementia occurrence. Among the combinations, dementia risk was higher in participants with a larger waist circumference and a smaller right thigh circumference, with the highest HR of 2.49 (95% CI = 1.54-4.03). CONCLUSION: The body measures provide clues for future applications and scientific merits in both clinical and preventive medicine.

Causes of Death in Different Subtypes of Ischemic and Hemorrhagic Stroke.

Causes of death in both ischemic stroke (IS) and hemorrhagic stroke (HS) subtypes are not comprehensively studied. Between 2008 and 2011, we enrolled 11 215 first-ever stroke patients from the Stroke Registry of Chang-Gung Healthcare System and linked these data to the national death registry. The main causes of death in each stroke subtype were assessed. Patients with HS had higher overall mortality than IS (32.0% vs 18.1%, P < .001). In IS subtypes, large-artery atherosclerosis plus cardioembolism had the worst mortality (40.7%, P < .001). Stroke was the leading cause of death in both IS and HS within the first year. Stroke remained the major cause of death in HS, but cancer was the leading cause of death in IS after the first year. After excluding the patients with previous cancer history, cancer was still an important cause of death in IS and HS, particularly in the IS subtypes of small vessel occlusion, stroke of undetermined etiology, and transient ischemic attack.

The influence of dehydration on the prognosis of acute ischemic stroke for patients treated with tissue plasminogen activator.

BACKGROUND: Many studies have determined that dehydration is an independent predictor of outcome after ischemic stroke (IS); however, none have determined if the use of thrombolytic therapy modifies the negative impact of poor hydration. To inform the stroke registry established at our institution, we conducted a retrospective study to determine if dehydration remains a negative prognostic factor after IS patients treated with tissue plasminogen activator (tPA). METHODS: Between 2007 and 2012, we recruited 382 subjects; 346 had data available and were divided into 2 groups on the basis of their blood urea nitrogen/creatinine (BUN/Cr) ratio. Dehydrated subjects had a BUN/Cr ratio ≥ 15; hydrated subjects had a BUN/Cr < 15. The primary outcome was impairment at discharge as graded by the Barthel Index (BI) and the modified Rankin Scale (mRS). RESULTS: The dehydration group had a greater mean age; more women; lower mean levels of hemoglobin, triglycerides, and sodium; and higher mean potassium and glucose levels. A favorable outcome as assessed by the mRS (≤2) was significantly less frequent among dehydrated subjects, but a favorable outcome by the BI (≥60) was not. Logistic regression and multivariate models confirmed that dehydration is an independent predictor of poor outcome by both the mRS and the BI; however, it was not predictive when patients were stratified by Trial of Org 10,172 in Acute Stroke Treatment subtype. CONCLUSIONS: Our findings indicate that use of thrombolytic therapy does not eliminate the need to closely monitor hydration status in patients with IS.

Risk factor analysis for meralgia paresthetica: A hospital-based study in Taiwan.

Recognizing the cause is essential for the management of meralgia paresthetica (MP), also known as lateral femoral cutaneous neuropathy. The aim of this study was to investigate the etiologies of MP and their influence on each other. This retrospective study enrolled referral patients with electromyographic studies who fulfilled the clinical and electrodiagnostic criteria of MP from January 2003 to December 2013. Data including age, gender, body weight, body height, occupation, and relevant medical history were collected. The etiological analysis was based on age and gender. A total of 50 patients (30 males and 20 females) were enrolled. The average age (±standard deviation) at diagnosis was 49.8±12.8years. Risk factors were identified in 29 cases (58.0%). More patients younger than 50years of age were male (73.1%, p=0.049). Peaks of age occurred between 41-50years in men and 51-60years in women. More males had a body mass index≥24kg/m2 (69.2% vs. 31.6%, p=0.012) and ≥27kg/m2 (34.6% vs. 0.0%, p=0.006). Overweight and obese patients were more vulnerable to occupational factors (50.0% vs. 19.0%, p=0.030). Only one case had diabetes mellitus (2%). Male middle-aged patients with a higher body mass index and certain occupations had an increased risk of MP. In contrast to the peak age distribution of the male patients, the frequency of developing MP was relatively even among the women at all ages. The cause was often obscure.

Derivation and Validation of a Scoring System for Intravenous Tissue Plasminogen Activator Use in Asian Patients.

BACKGROUND AND PURPOSE: As Chinese Asian populations have an increased risk of intracerebral hemorrhage (ICH) after intravenous tissue plasminogen activator (IV tPA), we aimed to design a rapid, clinically applicable risk scoring system to predict ICH and functional outcomes after IV tPA treatment in Asian ischemic stroke patients. METHODS: From January 2009 to December 2012, consecutive acute ischemic stroke patients treated with IV tPA recruited from the Stroke Registry in Chang Gung Healthcare System (SRICHS) in Taiwan and the National University Hospital of Singapore (NUHS) acute stroke database were used to create and validate a scoring system. Nomogram was created for ICH and 3-month mortality. RESULTS: In total, 932 patients were included in the study: 386 from SRICHS for the derivation of scoring system and 546 from NUHS to validate it. We used nomograms to assign weightage to the scoring system. The presence of atrial fibrillation, glucose level, and the National Institutes of Health Stroke Scale (NIHSS) score were significantly associated with the risk of ICH. Age, NIHSS score, hyperlipidemia, and the presence of post-tPA ICH were significantly associated with mortality. The areas under the curve of derivation and validation cohorts were .663 and .662 for ICH, and .808 and .790 for mortality, respectively. CONCLUSIONS: The scoring system using nomograms can provide a fast, practical, and user-friendly tool that allows physicians to predict the risk of ICH and functional outcomes with IV tPA treatment in a clinical setting.

Timing of Symptomatic Infarct Swelling Following Intravenous Thrombolysis in Acute Middle Cerebral Artery Infarction: A Case-Control Study.

BACKGROUND: The risk of symptomatic infarct swelling has been reported to be higher in patients treated with recombinant tissue plasminogen activator (rt-PA). The aim of this study was to evaluate the timing of symptomatic infarct swelling after rt-PA treatment. METHODS: We retrospectively analyzed 14 868 patients with acute ischemic stroke from a stroke registry databank. We recruited patients with massive middle cerebral artery (MCA) infarction and symptomatic infarct swelling and excluded those with parenchymal or symptomatic hemorrhage. Multiple linear regression and multivariate logistic regression analyses were used to estimate the impact of rt-PA on the timing of symptomatic infarct swelling. RESULTS: A total of 23 patients with rt-PA treatment and 117 patients without rt-PA treatment were included. The rt-PA treatment group had a lower rate of coronary artery disease (8.7% vs 32.5%; P = .023), lower severity of baseline National Institutes of Health Stroke Scale score (19 vs 23; P = .014), shorter duration of infarct swelling (27.6 vs 45.4 hours; P < .001), and higher rate of hemicraniectomy surgery (65.2% vs 28.2%; P =.001) than those without rt-PA treatment. After adjusting for variables in multiple linear regression analysis, rt-PA treatment and an elevated C-reactive protein level were associated with early symptomatic infarct swelling ( P = .014 and P = .041, respectively). The rt-PA treatment was an independent factor related to early symptomatic infarct swelling within 36 hours ( P = .005; odds ratio [OR]: 5.3; confidence interval [CI]: 1.65-17.0) or 48 hours ( P = .009; OR: 16.4; CI: 2.00-134). CONCLUSION: Intravenous rt-PA treatment may hasten the onset of cerebral edema and subsequent cerebral herniation in large MCA territory infarction.

Association between Atrial Fibrillation and Three-Year Mortality in Nondiabetic Patients with Acute First-Ever Ischemic Stroke.

BACKGROUND: Diabetes mellitus (DM) is a risk factor for atrial fibrillation (AF) and is known to be an important risk factor for death from stroke. The influence of AF on long-term outcomes in patients with ischemic stroke remains controversial. To clarify the exact influence of AF on stroke outcome and exclude the effect from DM, we investigated the influence of AF on the 3-year outcomes of nondiabetic patients with acute first-ever ischemic stroke. METHODS: Five-hundred seventy-four nondiabetic patients with acute first-ever ischemic stroke were enrolled and had been followed for 3 years. Patients were divided into 2 groups according to whether AF was diagnosed or not. Clinical presentations, risk factors for stroke, laboratory data, comorbidities, and outcomes were recorded. RESULTS: A total of 107 patients (18.6%) had AF. The age was significantly older in patients with AF. Total anterior circulation syndrome occurred more frequently among patients with AF (P < .001). The mean length of stay in the acute ward was significantly higher in patients with AF (P < .001). Furthermore, dependent functional status following discharge was higher in patients with AF (P < .001). Multivariate Cox regression revealed that AF is a significant predictor of 3-year all-cause mortality (hazard ratio = 1.98, 95% confidence interval = 1.07-3.67, P = .022). CONCLUSIONS: AF is associated with increased risk of 3-year mortality in nondiabetic patients with acute first-ever ischemic stroke. Careful cardiac evaluation and treatment are essential in patients with AF and stroke.

Association between pneumonia in acute stroke stage and 3-year mortality in patients with acute first-ever ischemic stroke.

The influence of pneumonia in acute stroke stage on the clinical presentation and long-term outcomes of patients with acute ischemic stroke is still controversial. We investigate the influence of pneumonia in acute stroke stage on the 3-year outcomes of patients with acute first-ever ischemic stroke. Nine-hundred and thirty-four patients with acute first-ever ischemic stroke were enrolled and had been followed for 3years. Patients were divided into two groups according to whether pneumonia occurred during acute stroke stage or not. Clinical presentations, risk factors for stroke, laboratory data, co-morbidities, and outcomes were recorded. The result showed that a total of 100 patients (10.7%) had pneumonia in acute stroke stage. The prevalence of older age, atrial fibrillation was significantly higher in patients with pneumonia in acute stroke stage. Total anterior circulation syndrome and posterior circulation syndrome occurred more frequently among patients with pneumonia in acute stroke stage (P<0.001 and P=0.009, respectively). Multivariate Cox regression revealed that pneumonia in acute stroke stage is a significant predictor of 3-year mortality (hazard ratio=6.39, 95% confidence interval=4.03-10.11, P<0.001). In conclusion, pneumonia during the acute stroke stage is associated with increased risk of 3-year mortality. Interventions to prevent pneumonia in acute stroke stage might improve ischemic stroke outcome.

Association between renal dysfunction and 3-year mortality in patients with acute first-ever ischemic stroke.

OBJECTIVE: The influence of renal dysfunction on the clinical presentation and outcomes of patients with acute ischemic stroke is still controversial. We investigate the influence of renal dysfunction on the outcomes of patients with acute first-ever ischemic stroke. METHODS: Nine-hundred thirty-four patients with acute first-ever ischemic stroke were enrolled and followed for 3 years. Renal function was assessed using the equation of the Modification Diet for Renal Disease for estimated glomerular filtration rate (eGFR). Serum creatinine levels were obtained within 3 days of acute stroke onset. Reduced eGFR was defined as eGFR<60ml/min/1.73m(2). Clinical presentation, risk factors for stroke, laboratory data, co-morbidities, and outcomes were recorded. RESULTS: Total 264 patients (28.3%) had a reduced eGFR. The prevalence of older age, hypertension, and atrial fibrillation was significantly higher in patients with a reduced eGFR. Total anterior circulation syndrome occurred more frequently among patients with a reduced eGFR (P=0.010). Multivariate Cox regression revealed that a reduced eGFR is a significant predictor of 3-year mortality (HR=1.67, 95% CI=1.06-2.62, P=0.026). CONCLUSION: Reduced eGFR during the acute stroke stage is associated with increased risk of 3-year mortality. Furthermore, risk of acute complications and poor functional outcomes following discharge was significantly higher in patients with a reduced eGFR.

Coexisting diseases of moyamoya vasculopathy.

BACKGROUND: Several coexisting diseases have been reported in patients with moyamoya vasculopathy (MMV), but studies of quasi-moyamoya disease (quasi-MMD) are rare. This study aims to investigate the frequency of known coexisting diseases in patients with quasi-MMD and to compare quasi-MMD with moyamoya disease (MMD). METHODS: Between 2000 and 2011, we retrospectively screened patients with International Classification of Diseases, Ninth Revision, code of 4375 (MMD) in the Health Information System of our hospital. The vascular images of each patient were confirmed by 2 neurologists and 1 neuroradiologist based on the diagnostic criteria of Japan Ministry of Health and Welfare. We excluded the patients with missing images and erroneous diagnosis. Demographics, coexisting diseases, laboratory data, treatment, and recurrent strokes were recorded. The eligible patients were divided into quasi-MMD and MMD groups according to the presence or absence of coexisting diseases. RESULTS: MMV was found in 90 patients including 37 (41.1%) quasi-MMD and 53 (58.9%) MMD. Atherosclerosis (32.4%) and thyroid disease (29.7%) were the leading coexisting diseases in quasi-MMD. Patients with MMD became symptomatic in a bimodal age distribution, whereas patients with quasi-MMD became symptomatic in a single-peak distribution. The prognosis of recurrent strokes was similar between quasi-MMD and MMD based on Kaplan-Meier analysis. CONCLUSIONS: A bimodal distribution of onset age was noted in MMD, whereas a single-peak distribution was found in quasi-MMD. Coexisting diseases were usually underevaluated but were more common than expected in patients with MMV. Atherosclerosis and thyroid diseases were the leading coexisting diseases in different preferential age.

Hypoxic preconditioning-induced mitochondrial protection is not disrupted in a cell model of mtDNA T8993G mutation-induced F1F0-ATP synthase defect: the role of mitochondrial permeability transition.

Transient opening of the mitochondrial permeability transition pore plays a crucial role in hypoxic preconditioning-induced protection. Recently, the cyclophilin-D component of the mitochondrial permeability transition pore has been shown to interact with and regulate the F1F0-ATP synthase. However, the precise role of the F1F0-ATP synthase and the interaction between cyclophilin-D and F1F0-ATP synthase in the mitochondrial permeability transition pore and hypoxic preconditioning remain uncertain. Here we found that a 1-h hypoxic preconditioning delayed apoptosis and improved cell survival after stimulation with various apoptotic inducers including H2O2, ionomycin, and arachidonic acid in mitochondrial DNA T8993G mutation (NARP) osteosarcoma 143B cybrids, an F1F0-ATP synthase defect cell model. This hypoxic preconditioning protected NARP cybrid cells against focal laser irradiation-induced oxidative stress by suppressing reactive oxygen species formation and preventing the depletion of cardiolipin. Furthermore, the protective functions of transient opening of the mitochondrial permeability transition pore in both NARP cybrids and wild-type 143B cells can be augmented by hypoxic preconditioning. Disruption of the interaction between cyclophilin-D and F1F0-ATP synthase by cyclosporin A attenuated the mitochondrial protection induced by hypoxic preconditioning in both NARP cybrids and wild-type 143B cells. Our results demonstrate that the interaction between cyclophilin-D and F1F0-ATP synthase is important in the hypoxic preconditioning-induced cell protection. This finding improves our understanding of the mechanism of mitochondrial permeability transition pore opening in cells in response to hypoxic preconditioning, and will be helpful in further developing new pharmacological agents targeting hypoxia-reoxygenation injury and mitochondria-mediated cell death.

mtDNA T8993G mutation-induced F1F0-ATP synthase defect augments mitochondrial dysfunction associated with hypoxia/reoxygenation: the protective role of melatonin.

BACKGROUND: F1F0-ATP synthase (F1F0-ATPase) plays important roles in regulating mitochondrial function during hypoxia, but the effect of F1F0-ATPase defect on hypoxia/reoxygenation (H/RO) is unknown. The aim of this study was to investigate how mtDNA T8993G mutation (NARP)-induced inhibition of F1F0-ATPase modulates the H/RO-induced mitochondrial dysfunction. In addition, the potential for melatonin, a potent antioxidant with multiple mitochondrial protective properties, to protect NARP cells exposed to H/RO was assessed. METHODS AND FINDINGS: NARP cybrids harboring 98% of mtDNA T8993G genes were established as an in vitro model for cells with F1F0-ATPase defect; their parental osteosarcoma 143B cells were studied for comparison. Treating the cells with H/RO using a hypoxic chamber resembles ischemia/reperfusion in vivo. NARP significantly enhanced apoptotic death upon H/RO detected by MTT assay and the trypan blue exclusion test of cell viability. Based on fluorescence probe-coupled laser scanning imaging microscopy, NARP significantly enhanced mitochondrial reactive oxygen species (mROS) formation and mitochondrial Ca(2+) (mCa(2+)) accumulation in response to H/RO, which augmented the depletion of cardiolipin, resulting in the retardation of mitochondrial movement. With stronger H/RO stress (either with longer reoxygenation duration, longer hypoxia duration, or administrating secondary oxidative stress following H/RO), NARP augmented H/RO-induced mROS formation to significantly depolarize mitochondrial membrane potential (ΔΨm), and enhance mCa(2+) accumulation and nitric oxide formation. Also, NARP augmented H/RO-induced mROS oxidized and depleted cardiolipin, thereby promoting permanent mitochondrial permeability transition, retarded mitochondrial movement, and enhanced apoptosis. Melatonin markedly reduced NARP-augmented H/RO-induced mROS formation and therefore significantly reduced mROS-mediated depolarization of ΔΨm and accumulation of mCa(2+), stabilized cardiolipin, and then improved mitochondrial movement and cell survival. CONCLUSION: NARP-induced inhibition of F1F0-ATPase enhances mROS formation upon H/RO, which augments the depletion of cardiolipin and retardation of mitochondrial movement. Melatonin may have the potential to rescue patients with ischemia/reperfusion insults, even those associated with NARP symptoms.