Incidence of oral anticoagulant interruption among stroke patients with atrial fibrillation and subsequent stroke

BACKGROUND AND PURPOSE

We analyzed the incidence and causes of oral anticoagulant (OAC) cessation and subsequent stroke after OAC withdrawal in a cohort of Korean stroke patients with atrial fibrillation.

METHODS

The Korean Atrial Fibrillation Evaluation Registry in Ischemic Stroke patients (K-ATTENTION) is a multicenter cohort study, merging stroke registries from 11 tertiary centers in Korea. The number of OAC interruption episodes and the reasons were reviewed from hospital records. Stroke after OAC withdrawal was defined when a patient experienced ischaemic stroke within 31 days after OAC withdrawal. Clinical variables were compared between patients who experienced stroke recurrence during OAC interruption and those who did not experience recurrence.

RESULTS

Among 3213 stroke patients with atrial fibrillation, a total of 329 episodes of OAC interruption were detected in 229 patients after index stroke (mean age 72.9 ± 8.3 years, 113 female patients). The most frequent reason for OAC withdrawal was poor compliance [103 episodes (31.3%)] followed by extracranial bleeding [96 episodes (29.2%)]. Stroke after OAC withdrawal was noted in 13 patients. Mean age, vascular risk factor profile and mean CHA₂ DS₂ -VASc score were not significantly different between patients with and without recurrent stroke.

CONCLUSIONS

A considerable number of stroke patients with atrial fibrillation experienced temporary interruption of OAC after index stroke, which was associated with stroke recurrence of 4.0 cases per 100 interruption episodes.

P3715Impact of sleep-disordered breathing on short-term functional outcomes in ischemic stroke patients: a cardiopulmonary coupling analysis using holter-monitoring

Background

Sleep-disordered breathing (SDB) assessed by conventional polysomnography is reported to have close association with worsened clinical outcomes in patients with ischemic stroke. The cardiopulmonary coupling (CPC) analysis using Holter-monitoring is an easily assessable method to evaluate SDB. However, its prognostic impact needs to be investigated.

Purpose

The present study investigated the prognostic impact of SDB defined by CPC analysis using Holter-monitoring at early stage of ischemic stroke on the functional disability at 3-month follow-up.

Methods

Total 692 patients with acute ischemic stroke who underwent Holter-monitoring were enrolled. The CPC analysis was conducted and SDB was defined as the presence of narrow-band (NB) coupling during sleep time. We investigated the association between SDB and functional disability at 3-month measured by modified Rankin scale (mRS).

Result

The NB coupling was present in 216 (31.2%) of 692 patients with mean age of 64.2±12.8 years. The NB group showed significantly higher proportion of severe functional disability (mRS ≥3; 45.3% vs. 12.3%, p<0.001) and persistent disability (ΔmRS≤0; 42.6% vs. 56.4%, p<0.001) after 3-month. In multivariate analysis, the presence of NB coupling was an independent predictor of higher risk of both severe and persistent functional disability (HR: 3.97; 95% CI: 2.37–6.64; p<0.001; and HR 1.92; 95% CI: 1.34–2.77; p<0.001, respectively). The results were consistent after propensity-score matched analysis with 175 patient pairs (C-statistics=0.759).

Parameters of functional disability Overall population (n=692) PSM population (n=350) no NB (n=476) NB (n=216) OR (95% CI) p-value no NB (n=175) NB (n=175) OR (95% CI) p-value Initial NIHSS ≥5 89 (18.6) 81 (37.5) <0.001 52 (29.7) 52 (29.7) >0.999 Discharge mRS ≥3 146 (30.6) 126 (58.3) <0.001 90 (51.4) 89 (50.8) 0.915 3-month mRS ≥3 59 (12.3) 98 (45.3) 5.86 (4.00–8.60) <0.001 38 (21.7) 72 (41.1) 2.52 (1.57–4.02) <0.001 3-month ΔmRS ≤0 (persisent disability) 203 (42.6) 122 (56.4) 1.74 (1.26–2.41) 0.001 77 (44.0) 100 (57.1) 1.69 (1.11–2.58) 0.014 Data are expressed as n (%). mRS = modified Rankin's scale; NB = narrow-band; NIHSS = National Institutes of Health Stroke Scale; OR = odds ratio; PSM = propensity-score matched.

Functional disabilities after 3-month

Conclusion

SDB assessed by CPC analysis at early phase of ischemic stroke was able to predict both greater and persistent functional disability at 3-month. The CPC analysis using Holter-monitoring is a useful modality for predicting functional disabilities in acute ischemic stroke.

P5744Sleep-disordered breathing assessed by holter-monitoring is associated to worsened one-year clinical outcomes in ischemic stroke patients: a cardiopulmonary coupling analysis

Background

Sleep-disorder breathing (SDB) using polysomnography is closely associated to poor functional and clinical outcomes in ischemic stroke patients. The cardiopulmonary coupling analysis using Holter-monitoring (CPC-Holter analysis) is an emerging feasible modality to investigate SDB.

Purpose

We investigated the association between SDB defined by CPC-Holter analysis and one-year clinical outcome in patients with acute ischemic stroke.

Methods

Total 666 patients with acute ischemic stroke who underwent Holter-monitoring were enrolled. The CPC-Holter analysis was conducted and SDB was defined as the presence of narrow-band (NB) coupling during sleep time. Primary outcome was recurrent ischemic stroke, and secondary outcome was major adverse cerebrovascular event (MACE), a composite of recurrent ischemic stroke, transient ischemic attack, and all-cause mortality within one year since discharge.

Result

The NB coupling was present in 205 (30.8%) of 666 patients with mean age of 64.1±12.8 years. The NB group showed significantly higher incidence of both recurrent ischemic stroke (8.3% vs. 1.4%, p<0.001) and MACE (14.9% vs. 3.0%, p<0.001) within one-year. In multivariate analysis, presence of NB coupling remained as an independent predictor of both recurrent ischemic stroke and MACE (HR: 4.81; 95% CI: 1.73–13.4; p=0.003; and HR 4.17; 95% CI: 1.74–10.0; p<0.001, respectively). The results were consistent after propensity-score matched analysis with 164 patient pairs (C-statistics=0.757).

One-year clinical outcomes Overall population (n=666) PSM population (n=328) no NB (=461) NB (n=205) Log-rank p-value OR (95% CI) no NB (n=164) NB (n=164) Log-rank p-value OR (95% CI) Recurrent ischemic stroke 6 (1.4) 14 (8.3) <0.001 5.73 (2.20–14.9) 3 (2.0) 11 (8.1) 0.026 3.85 (1.07–13.8) Transient ischemic attack 3 (0.7) 3 (1.7) 0.275 2 (1.3) 3 (2.1) 0.633 Hemorrhagic stroke 0 (0.0) 2 (1.2) 0.027 0 (0.0) 2 (1.5) 0.148 Total death 3 (0.7) 9 (4.8) 0.001 2 (1.3) 3 (1.9) 0.641 MACEs 12 (3.0) 25 (14.9) <0.001 4.63 (2.06–10.4) 7 (5.2) 17 (13.1) 0.030 2.95 (1.06–8.21) Data are expressed as n (%). CI = confidence interval; MACE = major adverse cardiovascular event; NB = narrow-band; OR = odds ratio.

One-year clinical outcomes

Conclusion

SDB assessed by CPC-Holter analysis at early phase of ischemic stroke is a powerful prognostic marker for predicting one-year adverse clinical outcomes. The CPC analysis using Holter-monitoring is a useful modality and could be easily applied to predict clinical outcomes in acute ischemic stroke patients.

Structural and functional characteristics of oestrogen receptor β splice variants: Implications for the ageing brain

Oestrogen receptor (ER)β is a multifunctional nuclear receptor that mediates the actions of oestrogenic compounds. Despite its well defined role in mediating the actions of oestrogens, a substantial body of evidence demonstrates that ERβ has a broad range of physiological functions independent of those normally attributed to oestrogen signalling. These functions can partly be achieved by the activity of several alternatively spliced isoforms that have been identified for ERβ. This short review describes structural differences between the ERβ splice variants that are known to be translated into proteins. Moreover, we discuss how these alternative structures contribute to functional differences in the context of both healthy and pathological conditions. Our review also describes the principal factors that regulate alternative RNA splicing. The alternatively spliced isoforms of ERβ are differentially expressed according to brain region, age and hormonal milieu, emphasising the likelihood that there are precise cell-specific mechanisms regulating ERβ alternative splicing. However, despite these correlative data, the molecular factors regulating alternative ERβ splicing in the brain remain unknown. We also review the basic mechanisms that regulate alternative RNA splicing and use that framework to make logical predictions about ERβ alternative splicing in the brain.

Fabrication of nitrogen-doped nano-onions and their electrocatalytic activity toward the oxygen reduction reaction

Nitrogen-doped nano-onions (NNO) were prepared as electrocatalytic materials for the oxygen reduction reaction (ORR). The nano-onions (NO), spherical graphitic material particles, were prepared by pyrolysis of nanodiamonds (ND). Oxidized NO (ONO) was prepared from NO by a modified Hummers’ method, and this was mixed with urea, followed by pyrolysis, resulting in the formation of NNO. The nitrogen content and molar ratio of nitrogen-containing groups in the NNOs were varied by controlling the oxygen content of ONO to explore the effect of nitrogen content on the ORR activity. The formation of NO was confirmed by Raman spectroscopy, X-ray diffraction analysis, and high-resolution transmission electron microscopy. X-ray photoelectron spectroscopy analyses were conducted to confirm the formation of the NNO and the structures of the nitrogen-containing groups in the NNOs. The ORR activities of the NNOs were investigated using a rotating disk electrode. The NNOs showed a higher onset potential than that of NO, and the ORR activity of the NNO could be improved by increasing the number of active sites (nitrogen-containing groups) in the NNO. In addition, the NNO exhibited better long-term stability and resistance toward methanol crossover in the ORR than the platinum-based catalysts.

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.

Prolonged sleep increases the risk of intracerebral haemorrhage: a nationwide case-control study

BACKGROUND AND PURPOSE

Although abnormal sleep duration is positively associated with increased risk for cardiovascular disease and mortality, the specific impact on intracerebral haemorrhage (ICH) risk remains unclear. The relationship between sleep duration and the risk of ICH was investigated in our study.

METHODS

A nationwide, multicentre matched case-control study was performed to investigate the risk factors for haemorrhagic stroke, using patients from 33 hospitals in Korea. In all, 490 patients with ICH and 980 age- and sex-matched controls were enrolled. Detailed information regarding sleep, sociodemographic factors, lifestyle and medical history before ICH onset was obtained using qualified structured questionnaires. Sleep duration was categorized and the adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using a conditional logistic regression with 7 h as the reference duration.

RESULTS

The number of subjects with long sleep duration, more than 8 h, was significantly greater in the ICH group than in the control group (≥8 h, 30.4% vs. 22.6%, P = 0.002). After controlling for relevant confounding factors, longer sleep duration was found to be independently associated with the risk of ICH in a dose-response manner (8 h, OR 1.57, 95% CI 1.00-2.47; ≥9 h, OR 5.00, 95% CI 2.18-11.47).

CONCLUSIONS

Our study suggested that long sleep duration is positively associated with an increased ICH risk in a dose-dependent manner. Further studies on the relationship linking long sleep duration with increased risk of ICH are required.

Creatine kinase isoenzyme activity during and after an ultra-distance (200 km) run

It is commonly assumed that creatine kinase (CK) activity in plasma is related to the state of an inflammatory response at 24-48 h, and also it has shown biphasic patterns after a marathon run. No information is available on CK isoenzymes after an ultra-marathon run. The purpose of the present study is to examine the CK isoenzymes after a 200 km ultra-marathon run and during the subsequent recovery. Blood samples were obtained during registration 1 2 h before the 200-km race and during the race at 100 km, 150 km and at the end of 200 km, as well as after a 24 h period of recovery. Thirty-two male ultra-distance runners participated in the study. Serum CPK showed a marked increase throughout the race and 24 h recovery period (p < 0.001). Serum CK during the race occurs mostly in the CK-MM isoform and only minutely in the CK-MB isoform and is unchanged in the CK-BB isoform. High-sensitivity C-reactive protein (hs-CRP), oestradiol, AST and ALT increased significantly from the pre-race value at 100 km and a further increase took place by the end of the 200 km run. The results of our study demonstrate a different release pattern of creatine kinase after an ultra-distance (200 km) run compared to the studies of marathon running and intense eccentric exercise, and changes in several biomarkers, indicative of muscle damage during the race, were much more pronounced during the latter half (100–200 km) of the race. However, the increases in plasma concentration of muscle enzymes may reflect not only structural damage, but also their rate of clearance.

Assessment of early therapeutic response to sorafenib in renal cell carcinoma xenografts by dynamic contrast-enhanced and diffusion-weighted MR imaging

OBJECTIVE

To investigate the feasibility of dynamic contrast-enhanced MRI (DCE-MRI) and diffusion-weighted MRI (DWI) in monitoring early therapeutic response to sorafenib in renal cell carcinoma (RCC) xenograft models.

METHODS

Sorafenib (40 mg kg(-1)) was administered orally to BALB/c nude mice (n = 9) bearing subcutaneous tumours of human RCC ACHN xenografts. DCE-MRI and DWI were obtained 0, 1, 3 and 7 days after therapy, and DCE-MRI parameters (K(trans) and ve) and apparent diffusion coefficient (ADC) values were calculated. Tumour size and volume changes were correlated with changes in DCE-MRI parameters or ADC values after therapy.

RESULTS

Following therapy, K(trans) showed a significant decrease over time (p = 0.005), whereas ve did not demonstrate significant changes between time points (p = 0.97). ADC values showed a progressive increase over time (p = 0.004). Compared with pre-therapy, K(trans) showed a significant decrease after 3 days of therapy (p = 0.039), and ADC values increased significantly after 7 days (p = 0.039). Tumour size and volume did not show significant changes during 7 days. Tumour size and volume changes were not associated with changes in DCE-MRI parameters or ADC values.

CONCLUSION

DCE-MRI and DWI may show early physiological changes within 1 week after initiating sorafenib treatment on human RCC xenografts.

ADVANCES IN KNOWLEDGE

The quantitative parameters of DCE-MRI and DWI may offer the potential for assessing early therapeutic response to sorafenib in clinical trials.

P42 Ebp1 regulates the proteasomal degradation of the p85 regulatory subunit of PI3K by recruiting a chaperone-E3 ligase complex HSP70/CHIP

The short isoform of ErbB3-binding protein 1 (Ebp1), p42, is considered to be a potent tumor suppressor in a number of human cancers, although the mechanism by which it exerts this tumor-suppressive activity is unclear. Here, we report that p42 interacts with the cSH2 domain of the p85 subunit of phosphathidyl inositol 3-kinase (PI3K), leading to inhibition of its lipid kinase activity. Importantly, we found that p42 induces protein degradation of the p85 subunit and further identified HSP70/CHIP complex as a novel E3 ligase for p85 that is responsible for p85 ubiquitination and degradation. In this process, p42 couples p85 to the HSP70/CHIP-mediated ubiquitin–proteasomal system (UPS), thereby promoting a reduction of p85 levels both in vitro and in vivo. Thus, the tumor-suppressing effects of p42 in cancer cells are driven by negative regulation of the p85 subunit of PI3K.

An assessment of oropharyngeal airway position using a fibreoptic bronchoscope

Selecting the appropriate oropharyngeal airway for safe and effective airway management is important in clinical practice. In this prospective observational study, we examined the position of the distal end of oropharyngeal airways using a fibreoptic bronchoscope. We enrolled 149 adults (72 men and 77 women). The correct airway size was determined by inserting four adult sizes Guedel airway (Hudson RCI; Teleflex Medical, Research Triangle, Park, NC, USA) (sizes 8, 9, 10 and 11) sequentially in anaesthetised patients. The 'best fit' airway was size 10 in 45 (62%) men, and size 9 in 58 (75%) women. However, when these airways were inserted, the distal end of the airway either touched or passed beyond the epiglottis tip in 20 (27%) men and six (8%) women, respectively. When a size-9 airway was inserted in men and a size-8 airway inserted in women, the distal ends were obstructed by the tongue in three (2%) patients. In conclusion, a size-9 airway in men and a size-8 airway in women are the most acceptable sizes for adults of average height.

Effects of Korean ginseng berry extract (GB0710) on penile erection: evidence from in vitro and in vivo studies

Several reports have promoted the root-derived Korean red ginseng (KRG; Panax ginseng) as alternative treatment for erectile dysfunction (ED), and ginsenosides are known to be the principal active ingredients of ginseng. Recent studies showed that ginseng berries produce more ginsenosides than KRG; thus, we investigated the ability of the Korean ginseng berry extract GB0710 to relax the penile corpus cavernosum smooth muscle (CCSM) in this study. As a comparative control, the results were compared to those obtained using KRG. In addition, possible mechanisms of action for GB0710 were investigated. While KRG and GB0710 both displayed dose-dependent relaxation effects on precontracted rabbit CCSM in vitro, GB0710 was shown to be more potent than KRG. The GB0710-induced relaxation could be partially reduced by removing the endothelium. In addition, pre-treatment with several nitric oxide (NO) inhibitors significantly inhibited the relaxation of muscle strips. Furthermore, administration of GB0710 increased intracavernosal pressure (ICP) in a rat in vivo model in both a dose- and duration-dependent manner. Intracellular NO production in human microvascular endothelial cells could be induced by GB0710 and inhibited by N(G)-monomethyl-L-arginine. In conclusion, GB0710 had a greater relaxation effect on rabbit CCSM than did KRG extract, and increased ICP in a rat model in both a dose- and a duration-dependent manner. This relaxing effect might be mediated by NO production.

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.

Solubility and stability of melatonin in propylene glycol and 2-hydroxypropyl-beta-cyclodextrin vehicles

The physicochemical properties of melatonin (MT) in propylene glycol (PG) and 2-hydroxypropyl-beta-cyclodextrin (2-HPbetaCD) vehicles were characterized. MT was endothermally decomposed as determined by differential scanning calorimetry (DSC). Melting point and heat of fusion obtained were 116.9+/-0.24 degrees C and 7249+/-217 cal/mol, respectively. MT as received from a manufacture was very pure, at least 99.9%. The solubility of MT in PG solution increased slowly until reaching 40% PG and then steeply increased. Solubility of MT increased linearly as concentration of 2-HPbetaCD without PG increased (R(2)=0.993). MT solubility in the mixtures of PG and 2-HPbetaCD also increased linearly but was less than the sum of its solubility in 2-HPbetaCD and PG individually. The MT solubility was low in water, simulated gastric or intestinal fluid but the highest in the mixture of PG (40 v/v%) and 2-HPbetaCD (30 w/v%) although efficiency of MT solubilization in 2-HPbetaCD decreased as the concentration of PG increased. MT was degraded in a fashion of the first order kinetics (r(2)>0.90). MT was unstable in strong acidic solution (HCl-NaCl buffer, pH 1.4) but relatively stable in other pH values of 4 approximately 10 at 70 degrees C. In HCl-NaCl buffer, MT in 10% PG was more quickly degraded and then slowed down at a higher concentration. However, the degradation rate constant of MT in 2-HPbetaCD was not changed significantly when compared to the water. The current studies can be applied to the dosage formulations for the purpose of enhancing percutaneous absorption or bioavailability of MT.

Determinants of muscle carnosine content

The main determinant of muscle carnosine (M-Carn) content is undoubtedly species, with, for example, aerobically trained female vegetarian athletes [with circa 13 mmol/kg dry muscle (dm)] having just 1/10th of that found in trained thoroughbred horses. Muscle fibre type is another key determinant, as type II fibres have a higher M-Carn or muscle histidine containing dipeptide (M-HCD) content than type I fibres. In vegetarians, M-Carn is limited by hepatic synthesis of β-alanine, whereas in omnivores this is augmented by the hydrolysis of dietary supplied HCD’s resulting in muscle levels two or more times higher. β-alanine supplementation will increase M-Carn. The same increase in M-Carn occurs with administration of an equal molar quantity of carnosine as an alternative source of β-alanine. Following the cessation of supplementation, M-Carn returns to pre-supplementation levels, with an estimated t_1/2 of 5–9 weeks. Higher than normal M-Carn contents have been noted in some chronically weight-trained subjects, but it is unclear if this is due to the training per se, or secondary to changes in muscle fibre composition, an increase in β-alanine intake or even anabolic steroid use. There is no measureable loss of M-Carn with acute exercise, although exercise-induced muscle damage may result in raised plasma concentrations in equines. Animal studies indicate effects of gender and age, but human studies lack sufficient control of the effects of diet and changes in muscle fibre composition.

Evaluation of virtual unenhanced CT obtained from dual-energy CT urography for detecting urinary stones

OBJECTIVE

The aim of our study was to determine if virtual unenhanced CT (VUCT) is equivalent to unenhanced CT (UCT) for detecting urinary stones.

METHODS

Our institutional review board approved this retrospective study, which was compliant with the Health Insurance Portability and Accountability Act. A total of 80 stones were detected in 32 patients among 146 consecutive patients undergoing dual-energy CT urography. The number and size of stones were recorded on nephrographic VUCT (NVUCT) and excretory VUCT (EVUCT) images, respectively. UCT was a reference of standard for the number and size of stones. Image quality of VUCT was qualitatively assessed using a five-point scale. Repeated-measures analysis of variance with post-test was used for statistical analysis.

RESULTS

62 stones in 29 patients were detected on NVUCT and 59 stones in 27 patients were detected on EVUCT. The size of stones detected on NVUCT or EVUCT was significantly smaller compared with stones on UCT (p<0.05). The size of stones detected on UCT, NVUCT and EVUCT ranged from 1.4 to 19.2 mm (mean, 4.6 mm), 0 to 19.2 mm (mean, 3.6 mm) and 0 to 18.7 mm (mean, 3.6 mm), respectively. 18 stones were missed on NVUCT and 21 were missed on EVUCT. The sizes ranged from 1.4 to 3.2 mm (mean, 2.1 mm) and 1.4 to 3.2 mm (mean, 2.2 mm) on UCT, respectively. VUCT was inferior to UCT regarding image quality (p<0.05).

CONCLUSION

VUCT missed a significant number of small stones probably owing to poor image quality compared with UCT. Subsequently, VUCT cannot replace UCT for detecting urinary stones.

Diffusion tensor imaging of normal prostate at 3 T: effect of number of diffusion-encoding directions on quantitation and image quality

OBJECTIVE

The purpose of this study was to prospectively investigate differences of diffusion tensor imaging (DTI) using a different number of diffusion-encoding directions and to evaluate the feasibility of tractography in healthy prostate at 3 T.

METHOD

12 healthy volunteers underwent DTI with single-shot echo-planar imaging at 3 T using a phased-array coil. Diffusion gradients of each DTI were applied in 6 (Group 1), 15 (Group 2) and 32 (Group 3) non-collinear directions. For each group, the mean apparent diffusion coefficient (ADC), fractional anisotrophy (FA) and signal-to-noise ratio (SNR) were measured in the peripheral zone (PZ) and central gland (CG). The quality of diffusion-weighted and tractographic images were also evaluated.

RESULTS

In all three groups, the mean ADC value of the CG was statistically lower than that of the PZ (p<0.01) and the mean FA value of the CG was statistically greater than that of the PZ (p<0.01). For the mean FA value of the CG, no statistical difference was seen among the three groups (p=0.052). However, the mean FA value of the PZ showed a statistical difference among the three groups (p=0.035). No significant difference in SNR values was seen among the three groups (p>0.05). Imaging quality of diffusion-weighted tractographic images was rated as satisfactory or better in all three groups and was similar among the three groups.

CONCLUSION

In conclusion, prostate DTI at 3 T was feasible with different numbers of diffusion-encoding directions. The number of diffusion-encoding directions did not have a significant effect on imaging quality.

Bronchial hyperresponsiveness to methacholine and adenosine 5'-monophosphate, and the presence and degree of atopy in young children with asthma

BACKGROUND

Bronchial hyperresponsiveness (BHR) is a characteristic feature of asthma, and is usually measured by bronchial challenges using direct or indirect stimuli. The relationship between atopy and BHR remains to be clarified, particularly in a population selected for asthma. Furthermore, data for young children are limited, although asthma frequently occurs in early childhood.

OBJECTIVE

The aim of this study was to investigate methacholine (direct stimulus) and adenosine 5'-monophosphate (AMP) (indirect stimulus) responsiveness according to the presence and degree of atopy in young children with asthma.

METHODS

A retrospective analysis of data from 122 preschool children (median age [range]: 5.3 years [4.0-6.8]) presenting with the diagnosis of asthma was performed. These children were characterized by skin-prick tests (SPTs) and bronchial challenges with methacholine and AMP, using a modified auscultation method. The end-point concentration, resulting in audible wheezing and/or oxygen desaturation, was determined for each challenge. Atopy was defined by at least one positive reaction to SPTs, and its degree was assessed using serum total IgE levels, number of positive SPTs, and atopic scores (sum of graded weal size).

RESULTS

Atopic patients (n=97) had a significantly lower AMP end-point concentration than non-atopic patients (n=25), whereas the methacholine end-point concentration was not different between the two groups. Among the atopic patients, there was no association between the methacholine end-point concentration and any of the atopy parameters. By contrast, a significant association was found between the AMP end-point concentration and the degree of atopy reflected in serum total IgE and atopic scores (χ² test for trend, P=0.001, 0.003, respectively).

CONCLUSION AND CLINICAL RELEVANCE

Young children with atopic asthma had a significantly greater AMP responsiveness than those with non-atopic asthma, whereas methacholine responsiveness was not significantly different between the two groups. The degree of atopy appeared to be an important factor in AMP responsiveness, but not in methacholine responsiveness, and thus might be a marker of airway inflammation in asthma.

Detection and characterization of enterovirus associated with herpangina and hand, foot, and mouth disease in Seoul, Korea

BACKGROUND

Human enteroviruses (HEVs) are a major cause of herpangina, HFMD (hand, foot, and mouth disease), and other neurological diseases in Seoul, Korea.

METHODS

A total of 56 specimens from hospitalized patients collected from February to December 2009 (37 females and 19 males) in Seoul were tested for HEV from stool, throat swab, and vesicle swab samples taken from patients with herpangina or HFMD using cell culture and RT-PCR in 2009. By the 1D gene, encoding the VP1 capsid protein, seven different HEV genotypes were detected with Coxsackievirus A2, A4, A5, A9, A16 (CA), Coxsackievirus B1 (CB), and Enterovirus 71 (EV71). The most prevalent genotype was CA16 (6, 10.7%), followed by CA2 (4, 7.1%), CA5 (4, 7.1%), EV71 (2, 3.6%), CA4 (1, 1.8%), CA9 (1, 1.8%), and CB1 (1, 1.8%). The 1D gene sequences of two EV71 strains were closely related with one another (98.5% nucleotide similarity) and belonged to the C4 genotype.

CONCLUSIONS

It is important to continuously survey the genetic characteristics of EV71 and CA16 from patients, which will provide useful data that aids in our understanding of HFMD infections in Seoul, Korea and may contribute to future control.

Viral agents associated with acute gastroenteritis in Seoul, Korea

BACKGROUND

The present study was carried out to describe the epidemiologic characteristics of viral gastroenteritis and determine the phylogenetic composition of norovirus strains detected in hospitalized children with acute gastroenteritis in Seoul, Korea.

METHODS AND RESULTS

In total, 10,603 stool samples were collected from 2004 to 2008 and tested by RT-PCR or ELISA. In 4,170 (39.3%) samples at least one viral pathogen was present. Rotavirus (RoV) (1,864, 17.5%) was found to be the causative agent followed by norovirus (NoV) (1,845, 17.4%), human adenovirus (HAdV) (266, 2.5%), human astrovirus (HAstV) (194, 1.8%), and sapovirus (SV) (1, 0.009%). Five GI genotypes (GI-1, GI-3, GI-4, GI-8, and GI-9) and eight GII genotypes (GII-2, GII-3, GII-4, GII-6, GII-7, GII-12, GII-16, and GII-17) of NoV were identified in acute gastroenteritis patients in 2008.

CONCLUSIONS

The genetic characteristics of norovirus and the epidemiologic patterns of a viral pathogen from acute gastroenteritis patients may give potentially effective data for epidemiological studies in Seoul, Korea.

A pilot study of brain activation in children with trichotillomania during a visual-tactile symptom provocation task: a functional magnetic resonance imaging study

OBJECTIVES

In order to reveal the etiology and pathophysiology of trichotillomania (TTM), it is necessary to investigate which brain regions are involved in TTM, but limited knowledge exists regarding the neurobiology of TTM and the available functional neuroimaging studies of TTM are little. The purpose of the present study was to investigate the specific brain regions involved in the pathophysiology of TTM with symptom provocation task using functional magnetic resonance imaging (fMRI) for children and adolescents with TTM.

METHODS

Pediatric subjects who met the DSM-IV TR criteria for TTM (n=9) and age-, sex-, handedness-, IQ matched healthy controls (HC) (n=10), ages 9 to 17 years, were recruited for two fMRI experiments; symptom provocation of Visual Only (VO) and Visual and Tactile (VT). They were scanned while viewing two alternating blocks of symptom provocation (S) and neutral (N) movies.

RESULTS

Random effects between-group analysis revealed significant activation in left temporal cortex(including middle and superior temporal gyrus), dorsal posterior cingulate gyrus, and putamen for the contrast S>N in TTM subjects versus HC subjects during the VO session. And TTM subjects demonstrated higher activity in the precuneus and dorsal posterior cingulate gyrus to the contrast S>N during the VT session.

CONCLUSIONS

This study provided an objective whole-brain-based analysis that directed researchers to areas that were abnormal in TTM. Using the symptom provocation tasks, we found significant differences in regional brain function between pediatric TTM and HC subjects. However, in the face of modest statistical power, our preliminary findings in TTM need to be replicated in a larger sample. As the functional neuroanatomic circuits involved in TTM remain largely unexplored, future functional neuroimaging studies using other various paradigms may help investigate the neuroanatomic abnormalities of TTM.

Prognostic significance of MRI-detected bladder muscle and/or serosal invasion in patients with cervical cancer treated with radiotherapy

In cervical cancer, the prognostic significance of bladder wall invasion on MRI without pathological evidence of mucosal invasion is not known. From 454 consecutive patients with cervical cancer who were treated with radiation, we reviewed images and analysed the outcome of 92 patients with the Federation of International Gynecology and Obstetrics (FIGO) stage IIIB-IVA. We analysed the patients in three groups, normal, wall (muscle and/or serosal) invasion and mucosal invasion, according to the findings on the MRI. Kaplan-Meier life table analysis and the log-rank test were used to assess the survival rates and differences according to prognostic factors. MRI detected abnormalities in the bladder wall in 42 patients (45.6%): wall invasion in 24 and mucosal invasion in 18. 5 of 18 patients, suspected on MRI to have mucosal invasion, showed no pathological evidence of mucosal invasion. Median follow-up period was 34 months. 3-year cause-specific survival (CSS) in the normal group compared with the wall invasion group was 76.2% vs 71.4% (p = 0.48). 3-year CSS for the wall invasion group compared with the mucosal invasion group was 71.4% vs 54.3% (p = 0.04). Mucosal invasion on MRI (p = 0.03) and concurrent chemoradiotherapy (p = 0.01) was significant for CSS. The prognosis for patients with cervical cancer with evidence of muscle and/or serosal invasion of the bladder on MRI may not differ from that for patients without abnormality on MRI. In patients with the MRI finding of bladder mucosal invasion, further studies should be conducted regarding the role of cystoscopy to determine the need for pathological confirmation.

Bronchial hyperresponsiveness to methacholine/AMP and the bronchodilator response in asthmatic children

Bronchodilator response (BDR) is assessed to estimate the reversibility of airflow obstruction. Bronchial hyperresponsiveness (BHR) is a characteristic feature of asthma and is usually measured by means of bronchial challenges using direct or indirect stimuli. The aim of the present study was to compare BHR to methacholine (direct) and that to adenosine 5'-monophosphate (AMP) (indirect) with regard to their relationships to BDR in asthmatic children. Methacholine and AMP challenge tests were performed on 138 children with mild-to-moderate asthma, and the provocative concentration causing a 20% decline in forced expiratory volume in 1 s (FEV₁) (PC₂₀) was determined for each challenge. BDR was calculated as the change in FEV(1), expressed as a percentage of the initial value, after inhalation of 400 μg salbutamol. Methacholine PC₂₀ correlated significantly but weakly with BDR (r = -0.254; p = 0.003). However, there was a significant and strong correlation between AMP PC₂₀ and BDR (r = -0.489; p = 0.000). For AMP PC₂₀, the relationship was closer than for methacholine PC₂₀ (p = 0.024 for comparison between correlation coefficients). The same figures were observed when BDR was expressed as a percentage of the predicted value. A stronger correlation of BDR with AMP PC₂₀ than with methacholine PC₂₀ suggests that BDR may be better reflected by BHR as assessed by AMP challenge than by methacholine challenge.

A Brownian energy depot model of the basilar membrane oscillation with a braking mechanism

High auditory sensitivity, sharp frequency selectivity, and spontaneous otoacoustic emissions are signatures of active amplification of the cochlea. The human ear can also detect very large amplitude sounds without being damaged, as long as the exposed time is not too long. The outer hair cells are believed to be the best candidate for the active force generator of the mammalian cochlea. In this paper, we propose a new model for the basilar membrane oscillation which describes both an active and a protective mechanism by employing an energy depot concept and a critical velocity of the basilar membrane. The compressive response of the basilar membrane at the characteristic frequency and the dynamic response to the stimulation are consistent with the experimental results. Although our model displays a Hopf bifurcation, our braking mechanism results in a hyper-compressive response to intense stimuli which is not generically observed near a Hopf bifurcation. Asymmetry seen in experimental recordings between the onset and the offset of the basilar membrane response to a sound burst is also observed in this model.

Validation of rapid methods for the determination of radiostrontium in milk

A rapid method of (89)Sr and (90)Sr comprising ion chromatography for preconcentration and Sr extraction chromatography for separation of Sr from Ca, Ba and Y was validated with spiked milk samples. An (89)Sr/(90)Sr activity ratio of up to 12 showed the relative bias was within +/-20%. The separation time of Sr was 7h and the chemical recovery of Sr ranged from 80% to 95%. The detection limit for 500 mL milk and 90 min counting time was 0.1 Bq L(-1).

Optimized fiber optic bioprobe with high spectral contrast exploiting laser-induced fluorescence for malignancy diagnosis

A high spectral contrast is expected to be very important when laser-induced fluorescence (LIF) is employed for cancer diagnosis. We developed a LIF optical fiber sensor to achieve a very high spectral contrast between normal and malignant tissues. A comprehensive experimental investigation was carried out to study the role of two critically important parameters for sensor design, namely, the excitation-collection geometry and the excitation wavelength, and their effect on the autofluorescence spectral contrast. An optimum sensing configuration was determined in order to enhance the small, but consistent, spectral difference between the normal and the malignant tissue for improving the accuracy of LIF-based cancer diagnosis. With the optimum sensor configuration, we realized a spectral contrast of more than 22 times between normal and malignant tissue sample spectra.

Prognostic factors influencing the development of an iatrogenic pneumothorax for computed tomography-guided radiofrequency ablation of upper renal tumor

BACKGROUND

Percutaneous radiofrequency (RF) ablation of upper renal tumors is considered a minimally invasive treatment, but this technique may cause pneumothorax.

PURPOSE

To assess retrospectively the prognostic factors influencing the development of iatrogenic pneumothorax for RF ablation of upper renal tumors.

MATERIAL AND METHODS

Computed tomography (CT)-guided RF ablation was performed in 24 patients (21 men, three women; age range 31-77 years, mean age 53.3 years) with 28 upper renal tumors. Various factors for pneumothorax-complicated (PC) upper renal tumors and non-pneumothoracic (NP) upper renal tumors were compared during RF ablation to determine which of the factors were involved in the development of pneumothorax.

RESULTS

Among 28 upper renal tumors in 24 patients, a pneumothorax occurred accidentally in six patients with eight tumors and intentionally in two patients with two tumors. This complication was treated with conservative management, instead of tube drainage. PC upper renal tumors had shorter distance from the lung or from the costophrenic line to the tumor, a larger angle between the costophrenic line and the tumor, and a higher incidence of intervening lung tissue than NP upper renal tumors (P<0.01). Intervening lung tissue was more frequently detected on CT images obtained with the patient in the prone position than on CT images obtained with the patient in the supine position.

CONCLUSION

The presence of intervening lung tissue and the close proximity between an upper renal tumor and the lung are high risk factors for developing an iatrogenic pneumothorax. Pre-ablation CT scan should be performed in the prone position to exactly evaluate intervening lung tissue.

Spontaneous rupture of pheochromocytoma: computed tomography-pathologic features and correlation

Spontaneous rupture is a rare complication of pheochromocytoma. Its preoperative diagnosis is of great importance in determining treatment and prognosis. We describe computed tomography pathologic findings and correlate their features in a case with ruptured pheochromocytoma.

Isolated tubal torsion: specific signs on preoperative computed tomography and magnetic resonance imaging

Isolated torsion of the fallopian tube is a rare cause of lower abdominal pain and commonly occurs after menarche. Prompt identification of this entity can prevent irreversible vascular damage, but the diagnosis is rarely made before surgery due to nonspecific clinical and imaging features. We report a case of isolated tubal torsion with specific imaging features on preoperative computed tomography and magnetic resonance imaging.

Relationships of methacholine and AMP responsiveness with peak expiratory flow variability in children with asthma

BACKGROUND

Both bronchial responsiveness (BR) and peak expiratory flow (PEF) variability are increased in asthma. PEF variability is presumed to reflect the degree of BR in asthma. BR is commonly assessed by bronchial challenges using direct or indirect stimuli.

OBJECTIVE

The aim of this study was to compare methacholine and adenosine 5'-monophosphate (AMP) responsiveness with regard to their relationships with PEF variability in children with asthma.

METHODS

Methacholine and AMP challenge tests were performed in 79 children with mild to moderate asthma, and a provocative concentration causing a 20% decline in forced expiratory volume in 1 s (PC(20)) was calculated for each challenge. Subjects recorded PEF each morning and each evening for 14 consecutive days. PEF variability was expressed as amplitude percentage mean (amp%mean; high PEF minus low PEF on each day, expressed as a percentage of their mean, averaged over 14 days), and as the lowest percentage highest (low%high; the lowest PEF expressed as a percentage of the highest PEF recorded over the period).

RESULTS

Methacholine PC(20) correlated significantly but weakly with both indices of PEF variability (amp%mean: r=-0.285, P=0.011; low%high: r=0.238, P=0.034). However, there was a significant and strong correlation between AMP PC(20) and both amp%mean (r=-0.583, P=0.000) and low%high (r=0.496, P=0.000). For AMP PC(20), the correlations were stronger than for methacholine PC(20) (comparison of correlation coefficients with amp%mean: P=0.021; with low%high: P=0.063).

CONCLUSION

Both methacholine PC(20) and AMP PC(20) correlated significantly with PEF variability. However, the stronger correlations for AMP PC(20) than for methacholine PC(20) suggest that PEF variability may be better reflected by BR assessed by AMP than by methacholine.