Experimental Evidence of Intrinsic Current Generation by Turbulence in Stationary Tokamak Plasmas.

High-ß_{θe} (a ratio of the electron thermal pressure to the poloidal magnetic pressure) steady-state long-pulse plasmas with steep central electron temperature gradient are achieved in the Experimental Advanced Superconducting Tokamak. An intrinsic current is observed to be modulated by turbulence driven by the electron temperature gradient. This turbulent current is generated in the countercurrent direction and can reach a maximum ratio of 25% of the bootstrap current. Gyrokinetic simulations and experimental observations indicate that the turbulence is the electron temperature gradient mode (ETG). The dominant mechanism for the turbulent current generation is due to the divergence of ETG-driven residual flux of current. Good agreement has been found between experiments and theory for the critical value of the electron temperature gradient triggering ETG and for the level of the turbulent current. The maximum values of turbulent current and electron temperature gradient lead to the destabilization of an m/n=1/1 kink mode, which by counteraction reduces the turbulence level (m and n are the poloidal and toroidal mode number, respectively). These observations suggest that the self-regulation system including turbulence, turbulent current, and kink mode is a contributing mechanism for sustaining the steady-state long-pulse high-ß_{θe} regime.

Clinical relevance of abnormal neuroimaging findings and long-term risk of stroke recurrence.

BACKGROUND AND PURPOSE: Previous studies have revealed that the predictors of short- and long-term stroke recurrence are different. We designed a comprehensive stroke recurrence (CSR) model, composed of demographic, clinical and radiological findings, to predict long-term ischaemic stroke recurrences. METHODS: We retrospectively collected the derivation cohort from consecutive patients with first-ever ischaemic stroke within 7 days of symptom onset. Univariate and multivariable Cox regression analysis were used to evaluate the association between 2-year recurrence and demographic, clinical and neuroradiological factors. The CSR score was calculated by adding the integer value of independent predictors that was derived from the ß-coefficient in the multivariable analysis. To qualify the model, we analyzed the receiver operating characteristics curve. We assessed internal validation with bootstrap methods and assessed external validation with another independent cohort. RESULTS: A total of 958 patients were enrolled, and 63 patients had recurrent strokes during the follow-up periods. The rate of stroke recurrence was 7.0% at 2 years. In the multivariable analysis, multiple stage lesions, isolated cortical lesions on diffusion-weighted imaging, severe white matter hyperintensities, multiple lacunar infarctions and relevant arterial stenosis were independently associated with stroke recurrence. The CSR model showed good discrimination [area under the curve (AUC), 0.81 (0.74-0.88)], which was consistent with internal [AUC, 0.75 (0.66-0.85)] and external [AUC, 0.80 (0.69-0.90)] validation. CONCLUSIONS: Abnormal neuroimaging findings, rather than cardiovascular risk factors, are predictive of long-term ischaemic stroke recurrence. Causative mechanism of stroke and underlying hostile brain milieu seem to be associated with long-term stroke recurrence.

Distal hyperintense vessel sign is associated with neurological deterioration in acute ischaemic stroke.

BACKGROUND AND PURPOSE: The aim was to evaluate the relationship between distal hyperintense vessel sign (HVS) and early neurological deterioration (END) in acute ischaemic stroke with large vessel steno-occlusion. METHODS: Acute ischaemic stroke patients with symptomatic severe steno-occlusion in the middle cerebral artery or internal carotid artery were recruited within 24 h from symptom onset. Stroke outcomes were evaluated using the National Institutes of Health Stroke Scale (NIHSS) score at the time of admission and at 72 h and 7 days. END was defined as an increment of ≥1 in the motor NIHSS score or ≥2 in the total NIHSS score. Distal HVS was defined as hyperintensity on fluid-attenuated inversion recovery image, located distal to the Sylvian fissure. The extent of distal HVS was divided into absent, subtle and prominent. RESULTS: Amongst a total of 325 participants, END was found in 103 (32%) patients. END was associated with age, atrial fibrillation, initial NIHSS score, initial infarct volume, severe leukoaraiosis, hemorrhagic infarction and distal HVS. In multivariate analysis, distal HVS remained an independent predictor of END [adjusted odds ratio (aOR) 2.86, 95% confidence interval (CI) 1.65-4.97, P < 0.001]. Initial infarct volume (aOR = 1.01, 95% CI 1.01-1.02, P < 0.001) and severe leukoaraiosis (aOR = 3.16, 95% CI 1.77-5.65, P < 0.001) were also associated with END, independently of distal HVS. In the analysis of the burden of distal HVS and stroke outcomes, prominent distal HVS was associated with stroke severity and infarct volume in a dose-response manner. CONCLUSIONS: Distal HVS is associated with END in acute ischaemic stroke patients with large vessel steno-occlusion.

D-dimer as a predictor of early neurologic deterioration in cryptogenic stroke with active cancer.

BACKGROUND AND PURPOSE: The occurrence of stroke in cancer patients is caused by conventional vascular risk factors and cancer-specific mechanisms. However, cryptogenic stroke in patients with cancer was considered to be more related to cancer-specific hypercoagulability. In this study, we investigated the potential of the D-dimer level to serve as a predictor of early neurologic deterioration (END) in cryptogenic stroke patients with active cancer. METHODS: We recruited 109 cryptogenic stroke patients with active cancer within 72 h of symptom onset. We defined END as an increase of ≥1 point in the motor National Institutes of Health Stroke Scale (NIHSS) score or ≥2 points in the total NIHSS score within 72 h of admission. After adjusting for potential confounding factors in the multivariate analysis, we calculated the odds ratios (ORs) and confidence intervals (CIs) of D-dimer in the prediction of END. RESULTS: Among 109 patients, END events were identified in 34 (31%) patients within 72 h. END was significantly associated with systemic metastasis, multiple vascular territory lesions on the initial magnetic resonance imaging (MRI), initial NIHSS score and D-dimer levels. In the multivariate analysis, the D-dimer level (adjusted OR, 1.11; 95% CI, 1.04-1.17; P < 0.01) and initial NIHSS score (adjusted OR, 1.08; 95% CI, 1.01-1.15; P = 0.03) predicted END after adjusting for potential confounding factors. In the subgroup analysis of 72 follow-up MRIs, D-dimer level was also correlated with new territory lesions on the follow-up MRI in a dose-dependent manner. CONCLUSION: Ischemic stroke patients with active cancer and elevated D-dimer levels appear to be at increased risk for END recurrent thromboembolic stroke.

Effects of celecoxib on hematoma and edema volumes in primary intracerebral hemorrhage: a multicenter randomized controlled trial.

BACKGROUND AND PURPOSE: We investigated the effect of celecoxib, a selective inhibitor of cyclo-oxygenase 2, in patients with intracerebral hemorrhage (ICH). METHODS: We conducted a multicenter, randomized, controlled, and open with blinded end-point trial of 44 Korean patients 18 years or older with ICH within 24 h of onset. The intervention group (n = 20) received celecoxib (400 mg twice a day) for 14 days. The control group (n = 24) received the standard medical treatment for ICH. The primary end-point was the number of patients with a change in the volume of perihematomal edema (PHE) from the 1st to the 7th ± 1 day (cut-off value, 20%). RESULTS: The time from onset to computed tomography scan slightly differed between groups (177 ± 160 min for control vs. 297 ± 305 min for the celecoxib group; P = 0.10). In the primary end-point analysis using cut-off values, there was a significant shift to reduced expansion of PHE in the celecoxib group (P = 0.005). With respect to the secondary end-points, there was also a significant shift to reduced expansion of ICH in the celecoxib group (P = 0.046). In addition, the expansion rate of PHE at follow-up tended to be higher in the control group than in the celecoxib group (90.6 ± 91.7% vs. 44.4 ± 64.9%; P = 0.058). CONCLUSIONS: In our small, pilot trial, administration of celecoxib in the acute stage of ICH was associated with a smaller expansion of PHE than that observed in controls.

Critical care management of patients with acute spinal cord injury.

Spinal cord injury (SCI) inevitably extends beyond neurologic consequences. The relationship between the spinal cord and its control of other organ systems make SCI management complex, requiring treatment on a multisystem approach. Patients frequently have hemodynamic instability and respiratory insufficiency secondary to the neurologic insult. Rigorous monitoring and anticipation of potential complications are essential in managing SCI, requiring a level of care provided in a neurocritical care unit. This review covers the pathophysiology, initial assessment, and stabilization in addition to acute management of cardiovascular and respiratory issues following SCI. Subsequent potential complications of deep vein thrombosis, gastrointestinal, and urinary systems and their management in the critical care setting are also addressed in this review.

Pulmonary function measures predict mortality differently in IPF versus combined pulmonary fibrosis and emphysema.

The composite physiologic index (CPI) was derived to represent the extent of fibrosis on high-resolution computed tomography (HRCT), adjusting for emphysema in patients with idiopathic pulmonary fibrosis (IPF). We hypothesised that longitudinal change in CPI would better predict mortality than forced expiratory volume in 1 s (FEV(1)), forced vital capacity (FVC) or diffusing capacity of the lung for carbon monoxide (D(L,CO)) in all patients with IPF, and especially in those with combined pulmonary fibrosis and emphysema (CPFE). Cox proportional hazard models were performed on pulmonary function data from IPF patients at baseline (n = 321), 6 months (n = 211) and 12 months (n = 144). Presence of CPFE was determined by HRCT. A five-point increase in CPI over 12 months predicted subsequent mortality (HR 2.1, p = 0.004). At 12 months, a 10% relative decline in FVC, a 15% relative decline in D(L,CO) or an absolute increase in CPI of five points all discriminated median survival by 2.1 to 2.2 yrs versus patients with lesser change. Half our cohort had CPFE. In patients with moderate/severe emphysema, only a 10% decline in FEV(1) predicted mortality (HR 3.7, p = 0.046). In IPF, a five-point increase in CPI over 12 months predicts mortality similarly to relative declines of 10% in FVC or 15% in D(L,CO). For CPFE patients, change in FEV(1) was the best predictor of mortality.

Comparison of 90-day case-fatality after ischemic stroke between two different stroke outcome registries using propensity score matching analysis.

BACKGROUND: It has not been clarified whether the disparity in ischemic stroke outcome between populations is caused by ethnic and geographic differences or by variations in case mix. Propensity score matching (PSM) analysis can overcome some analytical problems but is rarely used in stroke outcome research. This study was to compare the ischemic stroke case-fatality between two PSM cohorts of Sweden and Korea. METHODS: Prognostic variables related to baseline characteristics and stroke care were included in our PSM model. Then, we selected 7675 Swedish and 1220 Korean patients with ischemic stroke from each stroke registers and performed one-to-one matching based on propensity scores of each patient. RESULTS: After PSM, all measured variables were well balanced in 1163 matched subjects, and the 90-day case-fatality was identical 6.2% (HR 0.997, 95%CI 0.905-1.099) in Sweden and Korea. CONCLUSIONS: No difference is found in the 90-day case-fatality in propensity score-matched Swedish and Korean patients with ischemic stroke.

Prevalence and clinical correlates of bronchoreversibility in severe emphysema.

Chronic obstructive pulmonary disease (COPD) exhibits airflow obstruction that is not fully reversible. The importance of bronchoreversibility remains controversial. We hypothesised that an emphysematous phenotype of COPD would be associated with decreased bronchoreversibility. 544 patients randomised to the medical arm of the National Emphysema Treatment Trial formed the study group. Participants underwent multiple measurements of bronchoreversibility on a mean of four sessions over 1.91 yrs. They were also characterised by measures of symptoms, quality of life and quantitative measures of emphysema by computed tomography. Mean baseline forced expiratory volume in 1 s (FEV(1)) in this patient population is 24% predicted. 22.2% of patients demonstrated bronchoreversibility on one or more occasions using American Thoracic Society/European Respiratory Society criteria. Few patients (0.37%) had bronchoreversibility on all completed tests. Patients who demonstrated bronchoreversibility were more likely to be male, and have better lung function and less emphysema. 64% of patients demonstrated large (> or =400 mL) changes in forced vital capacity (FVC). In a severe emphysema population, bronchoreversibility as defined by change in FEV(1) is infrequent, varies over time, and is more common in males and those with less severe emphysema. Improvements in FVC, however, were demonstrated in the majority of patients.

Effect of cilnidipine vs losartan on cerebral blood flow in hypertensive patients with a history of ischemic stroke: a randomized controlled trial.

OBJECTIVES: The aim of this study was to compare the effects of antihypertensive agents on cerebral blood flow (CBF) in hypertensive patients with previous ischemic stroke. MATERIALS AND METHODS: In this double-blind, multi-center, non-inferiority trial, 196 patients were randomized to cilnidipine 10-20 mg or losartan 50-100 mg once daily for 4 weeks. Baseline and follow-up CBF as measured by single photon emission computed tomography were obtained in 167. The primary endpoint was the global CBF change. The secondary endpoints were the CBF change in the hemisphere ipsilateral to the index stroke, non-impairment of global CBF and blood pressure (BP) reduction. RESULTS: Global CBF increased significantly in the cilnidipine arm (9.0 +/- 29.6%, P = 0.0071) and the losartan arm (11.4 +/- 31.4%, P = 0.0012), and these changes were not different between the two groups (P = 0.607). However, the estimated difference in percentage global CBF change between the two groups was -2.43% (97.5% CI, -13.06% to 8.21%), which crossed the predetermined non-inferiority margin of -8.6%. Ipsilesional hemispheric CBF change, non-impairment of global CBF and BP reduction were similar in the two groups. CONCLUSIONS: This trial failed to prove the non-inferiority of cilnidipine to losartan regarding global CBF change. Both the treatments, however, increase the global CBF despite BP lowering.

Cordycepin inhibits IL-1beta-induced MMP-1 and MMP-3 expression in rheumatoid arthritis synovial fibroblasts.

OBJECTIVE: MMP is a key enzyme in the degradation of extracellular matrices, and its expression plays important roles in inflammatory diseases. Cordycepin (3'-deoxyadenosine), a bioactive compound of Cordyceps militaris, has been shown to exhibit many pharmacological activities, such as anti-cancer, anti-inflammatory and anti-infection activities. In this study, we aimed at the inhibitory effect of cordycepin on IL-1beta-induced MMP-1 and MMP-3 expression as well as the molecular basis using RA synovial fibroblasts (RASFs). METHODS: RASFs were isolated from synovial tissue obtained from 12 patients with RA and cultured in monolayer. Expression of MMP-1 and MMP-3 was evaluated using western blotting and real-time PCR. Chemokines were analysed by ELISA. The phosphorylation of mitogen-activated protein kinase was measured by western blotting. Electrophoretic mobility shift assay was performed to evaluate binding activities of DNA to nuclear factor-kappaB (NF-kappaB) and activator protein-1 (AP-1). RESULTS: Cordycepin inhibited IL-1beta-induced MMP-1 and MMP-3 expressions in RASFs in a dose-dependent manner. Among various chemokines [such as monocyte chemoattractant protein-1 (MCP-1), GRO-alpha, regulated upon activation, normal T-cell expressed and presumably secreted (RANTES) and epithelial neutrophil activating peptide 78 (ENA-78)], cordycepin specifically blocked IL-1beta-induced ENA-78 production in RASF. Moreover, cordycepin significantly inhibited IL-1beta-induced p38/JNK and AP-1 activation, but not extracellular signal-regulated kinase (ERK) and NF-kappaB activation. CONCLUSIONS: Cordycepin is a potent inhibitor of IL-1beta-induced chemokine production and MMP expression and strongly blocks the p38/JNK/AP-1 signalling pathway in RASFs.

Analgesia before a spinal block for femoral neck fracture: fascia iliaca compartment block.

BACKGROUND: In this prospective randomized study, the authors compared the analgesic effect of a fascia iliaca compartment (FIC) block with that of intravenous (i.v.) alfentanil when administered to facilitate positioning for spinal anaesthesia in elderly patients undergoing surgery for a femoral neck fracture. METHODS: The 40 patients were randomly assigned to one of two groups, namely, the FIC group (fascia iliaca compartment block, n=20) and the IVA group (intravenous analgesia with alfentanil, n=20). Group IVA patients received a bolus dose of i.v. alfentanil 10 microg/kg, followed by a continuous infusion of alfentanil 0.25 microg/kg/min starting 2 min before the spinal block, and group FIC patients received a FIC block with 30 ml of ropivacaine 3.75 mg/ml (112.5 mg) 20 min before the spinal block. Visual analogue pain scale (VAS) scores, time to achieve spinal anaesthesia, quality of patient positioning, and patient acceptance were compared. RESULTS: VAS scores during positioning (mean and range) were lower in the FIC group than in the IVA group [2.0 (1-4) vs. 3.5 (2-6), P=0.001], and the mean (+/- SD) time to achieve spinal anaesthesia was shorter in the FIC group (6.9 +/- 2.7 min vs. 10.8 +/- 5.6 min; P=0.009). Patient acceptance (yes/no) was also better in the FIC group (19/1) than in the IVA group (12/8)(P=0.008). CONCLUSIONS: An FIC block is more efficacious than i.v. alfentanil in terms of facilitating the lateral position for spinal anaesthesia in elderly patients undergoing surgery for femoral neck fractures.

[Spectrum analysis of pathological classification in 463 cases with nasal and paranasal sinuses malignant tumors].

Objective:The characteristics of pathological histological classification of nasal and paranasal sinuses malignant tumors in the past 10 years were analyzed, so as to provide possible basis, direction and ideas for the development of relevant effective treatment measures for nasal and paranasal sinuses malignant tumors in clinical practice. Method:The clinical data of patients with nasal and paranasal sinuses malignant tumors admitted to PLA general hospital from January 2009 to December 2018 were collected. Pathological types were retrospectively analyzed, and disease spectrum distribution, composition ratio and variation tendency of these patients were calculated. Result:Among the 463 patients, the overall pathological types in the top 5 were as follows: squamous cell carcinoma, adenoid cystadenocarcinoma, olfactory neuroblastoma, melanoma, adenocarcinoma. As for male patients, the pathological types in the top 5 were squamous cell carcinoma, adenoid cystic carcinoma, olfactory neuroblastoma, adenocarcinoma, neuroendocrine carcinoma and rhabdomyosarcoma were tied for fifth; the top 5 most common pathological types in female patients were squamous cell carcinoma, adenoid cystic carcinoma, melanoma, rhabdomyosarcoma, and adenocarcinoma. From 2009 to 2013, there were 183 patients with nasal and paranasal sinuses malignant tumors, the top 5 pathological types were squamous cell carcinoma, adenoid cystadenocarcinoma, olfactory neuroblastoma, melanoma, neuroendocrine carcinoma and rhabdomyosarcoma were tied for fifth; From 2014 to 2018, 280 patients with nasal and paranasal sinuses malignant tumors were diagnosed, the top 5 pathological types were squamous cell carcinoma, adenoid cystadenocarcinoma, melanoma, adenocarcinoma, and rhabdomyosarcoma. The ratio of the number of patients from 2009 to 2013 and 2014 to 2018 was about 0.65∶1. Malignant tumors of the nasal and paranasal sinuses tend to occur between the ages of 41 and 60, and the pathological types in the top 5 were squamous cell carcinoma,adenoid cystic carcinoma, adenocarcinoma, melanoma, neuroendocrine carcinoma. Conclusion:Malignant tumors of nasal cavity and sinus were more common in male, and the pathological types such as squamous cell carcinoma, adenoid cystic carcinoma, olfactory neuroblastoma were more common. All age groups have the disease, but the age group of 41-60 years old is the high-risk group of nasal and nasal sinus malignant tumors. However, the incidence rate of melanoma has gradually increased in the past five years, which needs to be paid more attention to.

Sex differences in physiological progression of idiopathic pulmonary fibrosis.

In idiopathic pulmonary fibrosis, incidence is higher in males, and females may have better survival. The aim of the present study was to determine whether the rate of increase in desaturation during serial 6-min walk testing would be greater, and survival worse, for males versus females. Serial changes in the percentage of maximum desaturation area (DA) over 1 yr were estimated using mixed models in 215 patients. DA was defined as the total area above the curve created using desaturation percentage values observed during each minute of the 6-min walk test. Multivariate Cox regression assessed survival differences. Adjusting for baseline DA, 6-min walk distance, change in 6-min walk distance over time and smoking history, the percentage of maximum DA increased by an average of 2.83 and 1.37% per month for males and females, respectively. Females demonstrated better survival overall, which was more pronounced in patients who did not desaturate below 88% on ambulation at baseline and after additionally adjusting for 6-month relative changes in DA and forced vital capacity. These data suggest that differences in disease progression contribute to, but do not completely explain, better survival of females with idiopathic pulmonary fibrosis.

Impact of neurological and medical complications on 3-month outcomes in acute ischaemic stroke.

OBJECTIVE: To evaluate the impact of neurological and medical complications on 3-month outcomes in acute ischaemic stroke patients. METHODS: We prospectively investigated complications for all the consecutive acute ischaemic stroke patients admitted within 7 days from onset in four university hospitals during a 1-year period. Baseline data and 3-month outcomes were collected. Poor outcome was defined as a modified Rankin Scale score 3-6. RESULTS: A total of 1 254 patients were recruited: 264 (21.1%) and 303 (24.2%) patients experienced one or more neurological and medical complications, respectively. The most common complications were ischaemic stroke progression (17.1%) and pneumonia (12.0%). Of 1 233 patients with available 3-month outcomes, 34.9% had a poor outcome. Multivariate analysis revealed that neurological (odds ratio, 95% confidence interval; 5.47, 3.63-8.24) and medical (3.47, 2.30-5.23) complications were independent predictors of the poor outcome. For the individual complications, ischaemic stroke progression (7.48, 4.73-11.84), symptomatic hemorrhagic transformation (3.57, 1.33-9.54), pneumonia (4.44, 2.20-8.99), extracranial bleeding (4.45, 1.88-10.53), and urinary tract infection (2.72, 1.32-5.60) were independently associated with the poor outcome. CONCLUSION: Outcome after ischaemic stroke is adversely influenced by complications, especially ischaemic stroke progression, symptomatic hemorrhagic transformation, pneumonia, extracranial bleeding, and urinary tract infection. Interventions to prevent those complications might improve ischaemic stroke outcome.

Hemispatial neglect in cerebellar stroke.

Cognitive deficits can be associated with cerebellar injury. The purpose of this study is to learn 1) if unilateral cerebellar injury might also cause hemispatial neglect, and if so, 2) if there is a left versus right asymmetry, 3) if the neglect is contralesional (CN) or ipsilesional (IN), and 4) if cerebellar injury might induce neglect by disruption of cerebellar-cortical networks. Participants were 28 patients with unilateral cerebellar stroke who were assessed for neglect within 2 months after the onset of stroke. To investigate if the cerebellar-cerebral network dysfunction induced neglect, 12 patients received perfusion single photon emission computed tomography (SPECT). Eight of the participants demonstrated neglect (28.6%), four with left cerebellar strokes (three with CN and one with IN) and four with right cerebellar strokes (three with IN and one with CN). Among five patients with neglect who had undergone SPECT, only one with ipsilesional neglect showed crossed cerebello-cerebral diaschisis. Neglect induced by cerebellar stroke might be more common than previously reported. Based on the cerebellar-cerebral network hypothesis we expected neglect to be more common with left than right cerebellar injury, but there was an equal number of patients with neglect from right and left sided strokes and the SPECT scan did not provide support of this hypothesis. Thus, this hypothesis cannot also explain the equal number of subject with ipsi- and contralesional neglect and in future studies alternative hypotheses such as vestibular hypothesis will have to be explored.

Feasibility of Permanent Stenting with Solitaire FR as a Rescue Treatment for the Reperfusion of Acute Intracranial Artery Occlusion.

BACKGROUND AND PURPOSE: The Solitaire FR can be used not only as a tool for mechanical thrombectomy but also as a detachable permanent stent. Our aim was to assess the feasibility and safety of permanent stent placement with the Solitaire FR compared with other self-expanding stents for intracranial artery recanalization for acute ischemic stroke. MATERIALS AND METHODS: From January 2011 through January 2016, we retrospectively selected 2979 patients with acute ischemic stroke. Among them, 27 patients who underwent permanent stent placement (13 patients with the Solitaire FR [Solitaire group] and 14 patients with other self-expanding stents [other stent group]) were enrolled. The postprocedural modified TICI grade and angiographic and clinical outcomes were assessed. The safety and efficacy of permanent stent placement of the Solitaire FR for acute large-artery occlusion were evaluated. RESULTS: Stent placement was successful in all cases. Modified TICI 2b-3 reperfusion was noted in 84.6% of the Solitaire group and in 78.6% of the other stent group. Procedural time was significantly shorter in the Solitaire group than in the other stent group (P = .022). Shorter procedural time was correlated with favorable outcome (ρ = 0.46, P = .035). No significant differences were found in the modified TICI grade, NIHSS score, mRS, and hemorrhagic transformation rate between the 2 groups. The acute in-stent thrombosis rate at discharge was significantly lower when a glycoprotein IIb/IIIa inhibitor was injected during the procedure (P = .013). CONCLUSIONS: Permanent stent placement with the Solitaire FR compared with other self-expanding stents appears to be feasible and safe as a rescue tool for refractory intra-arterial therapy.

Function of NAD glycohydrolase in ADP-ribose uptake from NAD by human erythrocytes.

The function of the ectoenzyme NAD glycohydrolase (NADase) in ADP-ribose uptake from extracellular NAD was studied in human erythrocytes that express relatively high NADase activity (adult erythrocytes) and erythrocytes expressing very low activity (newborn erythrocytes). The rates of ADP-ribose uptake from NAD in human erythrocytes were correlated with their NADase activities. In contrast, there was no significant difference in the rates of ADP-ribose uptake among these cells when incubated with ADP-ribose. These results indicate that ecto-NADase may have a role as supplier of ADP-ribose for its uptake into the cells and that the cleavage of NAD by NADase is necessary for the ADP-ribose uptake by human erythrocytes. From ADP-ribose uptake studies at 37 degrees C a Km of 0.7 +/- 0.05 microM and a Vmax of 2.04 +/- 0.1 pmol/min per microliter cell water was found for the uptake of [3H]ADP-ribose. The thiol-reactive reagents p-chloromercuribenzene sulfonic acid and N-ethylmaleimide inhibited the uptake ADP-ribose with IC50 values of 50 +/- 4 and 750 +/- 25 mM, respectively. Since efflux of [3H]ADP-ribose was negligible, the ADP-ribose transport system appears to be unidirectional. The unidirectionality was supported by the evidence that transported ADP-ribose was rapidly degraded to AMP which is impermeable to the membrane.

Glycosylphosphatidylinositol-anchored NAD glycohydrolase is released from peritoneal macrophages activated by interferon-gamma and lipopolysaccharide.

We have previously shown that an ectoenzyme, NAD glycohydrolase (NADase) could be solubilized by treatment with bacterial phosphatidylinositol phospholipase C (PIPLC). However, it is unknown whether endogenous PIPLC can cleave this ectoenzyme. In this study, we used mouse peritoneal exudate macrophages which have been known to have relatively high activity of NADase. The results show that release of ecto-NADase was markedly increased when mouse peritoneal macrophages were costimulated with interferon-gamma (IFN-gamma) and bacterial lipopolysaccharide (LPS), compared to unstimulated cells. This increase was preceded by markedly enhanced activity of endogenous glycosylphosphatidylinositol phospholipase C (GPIPLC). The cross-reacting determinant (CRD) of the glycosylphosphatidylinositol anchor in released NADase from activated macrophages was detected by immunoblotting with anti-CRD antibody. Taken together, ecto-NADase is release from peritoneal exudate macrophages during IFN-gamma/LPS-induced activation and endogenous GPIPLC is involved in the NADase release from the activated macrophages.

Purification and characterization of adenosine diphosphate ribose pyrophosphatase from human erythrocytes.

Free ADP-ribose is a turnover product of NAD+, protein-bound polymeric and monomeric ADP-ribose, and cyclic ADP-ribose. But little is known about the specific cellular roles or metabolism of free ADP-ribose. ADP-ribose pyrophosphatase (EC 3.6.1.13), which hydrolyzes ADP-ribose into AMP and ribose-5'-phosphate, was purified from human erythrocytes. Purification was achieved to homogeneity by successive chromatographic steps, resulting in a final purification of 75,790-fold from the hemolysate. The purified enzyme showed a single band with the molecular weight of 34 kDa on SDS-PAGE both in the presence and absence of 2-mercaptoethanol. The molecular weight of the native enzyme calculated by gel filtration was 68 kDa, indicating that the active enzyme is a dimer of identical subunits. The enzyme requiring Mg2+ showed highest activity toward ADP-ribose, and about 40-70% activities with IDP-ribose, ADP-mannose and GDP-mannose. The enzyme showed a Km of 169 +/- 11 microM for ADP-ribose, broad pH optimum around pH 9.5, and pI of 5.1. ADP was a potent noncompetitive inhibitor with a Ki of 16 +/- 1.2 microM. These results suggest that our enzyme is unique, and different from the other ADP-ribose pyrophosphatases reported. ADP-ribose pyrophosphatase may play an important role in the regulation of intracellular steady-state of free ADP-ribose.