Konjac Glucomannan Attenuated Triglyceride Metabolism during Rice Gruel Tolerance Test.

In a recent study, we showed that konjac glucomannan (KGM) inhibits rice gruel-induced postprandial increases in plasma glucose and insulin levels. To extend this research, we investigated the effects of KGM addition to rice gruel on pre- and postprandial concentrations of circulating lipoprotein lipase (LPL), glycosylphosphatidylinositol-anchored high-density lipoprotein-binding protein 1 (GPIHBP1), hepatic triglyceride lipase (HTGL), free fatty acids (FFA), and triglycerides (TG). A total of 13 Japanese men, without diabetes, dyslipidemia, or gastrointestinal diseases, interchangeably ingested rice gruel containing no KGM (0%G), rice gruel supplemented with 0.4% KGM (0.4%G), and rice gruel supplemented with 0.8% KGM (0.8%G), every Sunday for 3 weeks. Blood samples were obtained at baseline and at 30, 60, and 120 min after ingestion to measure the abovementioned lipid parameters. Lipid parameters showed small, but significant, changes. Significant reductions were found in circulating FFA levels among all participants. Circulating TG levels significantly declined at 30 min and then remained nearly constant in the 0.8%G group but exhibited no significant difference in the 0%G and 0.4%G groups. Although circulating levels of LPL and GPIHBP1 significantly decreased in the 0%G and 0.4%G groups, they increased at 120 min in the 0.8%G group. Participants in the 0%G and 0.4%G groups showed significant decreases in circulating HTGL levels, which was not observed in the 0.8%G group. Our results demonstrate the novel pleiotropic effects of KGM. Supplementation of rice gruel with KGM powder led to TG reduction accompanied by LPL and GPIHBP1 elevation and HTGL stabilization, thereby attenuating TG metabolism.

Improved Volitional Recall of Motor-Imagery-Related Brain Activation Patterns Using Real-Time Functional MRI-Based Neurofeedback.

Motor imagery (MI), a covert cognitive process where an action is mentally simulated but not actually performed, could be used as an effective neurorehabilitation tool for motor function improvement or recovery. Recent approaches employing brain-computer/brain-machine interfaces to provide online feedback of the MI during rehabilitation training have promising rehabilitation outcomes. In this study, we examined whether participants could volitionally recall MI-related brain activation patterns when guided using neurofeedback (NF) during training. The participants' performance was compared to that without NF. We hypothesized that participants would be able to consistently generate the relevant activation pattern associated with the MI task during training with NF compared to that without NF. To assess activation consistency, we used the performance of classifiers trained to discriminate MI-related brain activation patterns. Our results showed significantly higher predictive values of MI-related activation patterns during training with NF. Additionally, this improvement in the classification performance tends to be associated with the activation of middle temporal gyrus/inferior occipital gyrus, a region associated with visual motion processing, suggesting the importance of performance monitoring during MI task training. Taken together, these findings suggest that the efficacy of MI training, in terms of generating consistent brain activation patterns relevant to the task, can be enhanced by using NF as a mechanism to enable participants to volitionally recall task-related brain activation patterns.

Characteristics of Residual Atrial Posterior Wall and Roof-Dependent Atrial Tachycardias after Pulmonary Vein Isolation.

BACKGROUND: Roof-dependent atrial tachycardia (roof AT) sometimes occurs after pulmonary vein isolation (PVI) of atrial fibrillation (AF). This study aimed to investigate the relationship between the anatomy of the residual left atrial posterior wall and occurrence of roof AT. METHODS: A total of 265 patients with AF who underwent PVI were enrolled. After the PVI, induced or recurrent roof AT was confirmed by an entrainment maneuver or activation mapping using a three-dimensional (3D) mapping system. To identify the predictors of roof AT, the minimum distance between both PVI lines (d-PVI) was measured by a 3D mapping system and the anatomical parameters, including the left atrial (LA) diameter, left atrial volume index (LAVi), and shape of the left atrial roof, were analyzed by 3D computed tomography. RESULTS: Roof AT was documented in 11 (4.2%) of 265 patients. A multivariable analysis demonstrated that the d-PVI, Deep V shape of the LA roof, and LAVi were associated with roof AT occurrences (d-PVI: odds ratio: 0.72, confidence interval [CI]: 0.61-0.86, P < 0.001; Deep V shape: odds ratio: 0.19, CI: 0.04-0.82, P = 0.03; LAVi: odds ratio: 1.05, CI: 1.02-1.07, P = 0.001). A receiver-operating characteristic curve analysis yielded an optimal cut-off value of 15.5 mm and 55.7 mL/m2 for the d-PVI and LAVi, respectively. CONCLUSION: The shorter d-PVI at the LA roof, greater LAVi, and Deep V shape were associated with the occurrence of a roof AT.

The Relationship Between Cardiac Vulnerability and Restitution Properties of the Ventricular Activation Recovery Interval.

INTRODUCTION: The restitution of the action potential duration (APD) is an important contributor to ventricular fibrillation (VF) initiation by a single critically timed ectopic beat. We hypothesized that a steep slope of the activation recovery interval restitution curve was related to the upper limit of vulnerability (ULV). METHODS AND RESULTS: Fifty-four consecutive patients with implantable cardioverter defibrillators (ICDs) implanted between April 2012 and July 2013 were included. At the implantation, pacing from the right ventricular (RV) coil to an indifferent electrode inserted in the ICD pocket was performed, and the unipolar electrograms from the RV coil were simultaneously recorded. We assessed the standard restitution by introducing extra-stimuli, while measuring the activation recovery interval (ARI). Our protocol for the vulnerability test consisted of delivering three 15 J shocks on the T-peak and within ±20 milliseconds of it. If VF was not induced by that procedure, a ULV of ≤15 J was defined. The relationship between the ULV and maximum slope of the restitution curve was analyzed. A restitution curve could finally be obtained in a total of 40 patients. The background characteristics were similar between the two groups. The maximum slope of the restitution curve was steeper in the ULV > 15 J group than ULV ≤ 15 J group (1.55 ± 0.45 vs. 0.91 ± 0.64, P < 0.05). A maximum slope exceeding 1.0 was the optimal point for discriminating patients with a ULV > 15 J from a ULV ≤ 15 J (sensitivity 61.5% and specificity 96.3%). CONCLUSION: The maximum slope of the restitution curve was significantly related to the ULV. High defibrillation threshold patients could be detected by the ARI dynamics.

Crista Terminalis as the Anterior Pathway of Typical Atrial Flutter: Insights from Entrainment Map with 3D Intracardiac Ultrasound.

BACKGROUND: The precise location of truly active reentry circuits of typical atrial flutter (AFL) has not been well identified. The purpose of this study was to verify our hypothesis that the posterior block line is located along the posteromedial right atrium (PMRA) and the crista terminalis (CT) is the anterior pathway of AFL, with real-time intracardiac echo (ICE). METHODS: The entire right atrium (RA) three-dimensional activation and entrainment mapping were evaluated during AFL in 18 patients using CARTO sound. RESULTS: The CT was clearly visualized by ICE and the local electrograms along the CT were single potentials in all the patients. The CT was recognized as the truly active anterior pathway based on entrainment mapping in all patients. Double potentials were recorded along the PMRA. Entire RA entrainment mapping could be performed in 16 patients. The reentry circuits were separated into three passages. The first was around the tricuspid annulus (TA), the second the anterior superior vena cava (SVC; AFL waves passed between the anterior SVC and RA appendage), and the last the posterior SVC (between the posterior SVC and upper limit of the PMRA). All three of these passages were active in four, around the TA and anterior SVC in eight, around the TA and posterior SVC in three, and around only the anterior SVC in one patient. CONCLUSIONS: The CT functions as the anterior pathway of typical AFL, and the posterior block line was located along the PMRA. Dual or triple circuits were recognized in the majority of AFL patients.

Visualization of the antegrade fast and slow pathway inputs in patients with slow-fast atrioventricular nodal reentrant tachycardia.

INTRODUCTION: Mapping of the antegrade fast pathway (A-FP) exact sites and antegrade slow pathway (A-SP) input locations has not been well described. METHODS: In 56 patients with slow-fast atrioventricular nodal reentrant tachycardia (SF-AVNRT), pacing during sinus rhythm and entrainment pacing during SF-AVNRT were performed at various sites in the triangle of Koch and coronary sinus (CS) to identify the A-FP and A-SP inputs. User-defined three-dimensional electro-anatomical mapping of the stimulus-His potential (St-H) interval and anatomical location was performed. The A-FP input was defined as the site of the shortest St-H interval, and A-SP input as the site of the shortest St-H interval and with a postpacing-interval equal to the tachycardia cycle length. The locations of the A-FP and A-SP inputs were mapped as a ratio of the distance between the His bundle (HB) and CS orifice (CSO), and the HB-CSO axis was divided into three zones: superior-, mid-, and inferior septum. The distance between the A-SP and A-FP inputs was calculated using the distance from each input to the HB and HB-CSO axis. RESULTS: Only 30 patients were included in this study because the A-SP mapping failed in 26. The A-SP input was distributed to the superior septum in four, mid- or inferior septum in 25, and CS in one. An A-SP input which was located less than 10 mm from the A-FP input was observed in one of four patients with a superior septum A-SP. CONCLUSIONS: An A-SP input at the superior septum seemed to be a potential risk for atrioventricular nodal injury during ablation.

Rate-dependent and site-specific conduction block at the posterior right atrium and drug effects evaluated using a noncontact mapping system in patients with typical atrial flutter.

INTRODUCTION: Conduction block in the posterior right atrium (RA) plays an important role in perpetuating atrial flutter (AFL). Although conduction blocks have functional properties, it is not clear how the block line changes with the pacing rate, pacing site, and administration of antiarrhythmic drugs. METHODS AND RESULTS: Forty patients with typical AFL were enrolled. Pacing (110, 170, 230 ppm) from the coronary sinus ostium (CSo) and low lateral RA was performed. After 1 mg/kg pilsicainide (pure sodium channel blockade) administration, the pacing protocol was repeated. Conduction block was assessed based on a color-coded isopotential map and 20 points of virtual unipolar electrograms in the posterior RA using noncontact mapping. Block line proportion was defined as the percentage of length of the block line between the superior and inferior vena cava. The pacing rate-dependent extension of the block proportion was significant during pacing from both sides (pacing from the CSo: 59 ± 17% at 110 ppm, 69 ± 16% at 230 ppm, P < 0.05; pacing from the low lateral RA: 43 ± 19% at 110 ppm, 55 ± 22% at 230 ppm, P < 0.05). The block line was significantly longer during CSo pacing than during low lateral RA pacing at each rate (all P < 0.05). After pilsicainide administration, the block line extended further. CONCLUSION: In addition to pacing rate-dependent and site-dependent changes in the block line, pilsicainide further extended the block line length. This phenomenon explains the clinical observation that counterclockwise AFL occurs more frequently than clockwise AFL, and the mechanism of class IC AFL.

Utility of virtual unipolar electrogram morphologies to detect transverse conduction block and turnaround points of typical atrial flutter.

BACKGROUND: Noncontact mapping is useful for the diagnosis of various arrhythmias. Virtual unipolar electrogram morphologies (VUEM) of the conduction block and the turnaround points, however, are not well defined. We compared the VUEM characteristics of a transverse conduction block in the posterior right atrium (RA) with those of contact bipolar electrograms obtained during typical atrial flutter (AFL). METHODS: Contact bipolar electrograms were used to map the posterior RA during typical AFL in 16 patients. Twenty points of the VUEM recorded along the block line were analyzed and compared with contact bipolar electrograms. RESULTS: Seventeen AFLs were analyzed. Fifteen AFLs showed an incomplete transverse conduction block in the posterior RA by contact bipolar mapping. A double potential on the block line corresponded to the two components of the VUEM, in which the second component showed an Rs, RS, or rS pattern. At the turnaround point, a fused double potential of the contact bipolar electrograms corresponded to a change of the second component of the VUEM from an rS to a QS morphology. Two AFLs showed a complete block line in the posterior RA. The contact bipolar electrogram showed double potentials from the inferior vena cava to the superior vena cava, whereas the second component of the VUEM remained in an unchanged Rs, RS, or rS pattern. CONCLUSION: VUEM analysis was a reliable method for identifying the posterior block line during AFL. This method may also be applicable for detecting block lines and turnaround points of circuits in other unmappable arrhythmias.

Relationship between root caries and alveolar bone loss in the first wet-rice agriculturalists of the Yayoi period in Japan.

OBJECTIVE: The people of the Yayoi period (5th C b.c.-3rd C a.d.), who were the first wet-rice agriculturalists in ancient Japan, had carious lesions that were most frequently located on the root surfaces of their teeth. Root surface exposure is a prerequisite for this type of decay, and alveolar bone loss is the main cause of such exposure. Therefore, we identify the factors associated with root caries, and examine the relationship between root caries and alveolar bone loss in the people of the Yayoi period. MATERIALS AND METHODS: This study was performed using 263 sets of ancient skeletal remains that are believed to be from the Yayoi period and that were excavated at 49 archaeological sites in western Japan. Using 5010 teeth found among the remains, we analysed the relationship between the prevalence of root caries and the cemento-enamel junction-alveolar crest (CEJ-AC) distance. RESULTS: The prevalence of root caries and the mean number of teeth with root caries per person were significantly correlated with age, the presence of coronal caries and the mean CEJ-AC distance per person. We also found that as the mean CEJ-AC distance per tooth surface increased, the percentage of the root surface affected by caries increased. Moreover, after excluding the lingual (palatal) side, the mean CEJ-AC distance per surface was significantly greater for those tooth surfaces with root caries. CONCLUSION: We present the first evidence that the occurrence of root caries correlated with the CEJ-AC distance in the Yayoi people of Japan.

Identification of the right ventricular pacing site for cardiac resynchronization therapy (CRT) guided by electroanatomical mapping (CARTO).

BACKGROUND: The optimal left ventricle (LV) pacing site for cardiac resynchronization therapy (CRT) has been investigated, but less is known about the optimal site in the right ventricle (RV). The present study examined whether electrical resynchronization guided by electroanatomical mapping (CARTO) results in mechanical resynchronization. METHODS AND RESULTS: The study group included 13 patients indicated for CRT: 10 with nonischemic cardiomyopathy, 2 with ischemic cardiomyopathy and 1 with cardiac sarcoidosis, (mean LV ejection fraction: 32+/-10%). CARTO of the RV septum was performed to identify the site with the most delayed conduction time during LV pacing. Hemodynamic measurements were performed during conventional biventricular pacing with the RV apex and LV (C-BVP) and during biventricular pacing with the most delayed site of the RV (d-RV) and LV (D-BVP). Lead placement at 15 coronary sinus veins was examined in the 13 patients. During pacing from anterolateral veins (n=2), the d-RV was the RV apex (RVA) in 1 patient and the mid-septum in the other. During pacing from lateral veins (n=9), the d-RV comprised the RVA (n=3), the mid-septum (n=5), and the right ventricular outflow tract (RVOT) (n=1). During pacing from the posterolateral veins (n=3), the d-RV was the RVOT in all cases. In 11 of 15 sites, d-RV differed from conventional RVA. Compared with C-BVP, D-BVP produced a significant improvement in LV dp/dt. Furthermore, RV mid-septum and LV pacing markedly increased LV dp/dt and pulse pressure (PP), but RVOT and LV pacing did not. D-BVP vs C-BVP: %LV dp/dt 30+/-20 and 15+/-15%, p<0.05; RV mid-septum and LV pacing vs C-BVP: %LV dp/dt 35+/-20 and 10+/-15%, p<0.02, and vs PP 33+/-20 and 10+/-29 mmHg, p<0.02. CONCLUSIONS: For pacing from the LV lateral vein, potential improvement of cardiac performance compared with that by conventional RVA placement may be realized with concomitant pacing from the d-RV (mid-septum).

Predictive value of microvolt T-wave alternans for sudden cardiac death in patients with preserved cardiac function after acute myocardial infarction: results of a collaborative cohort study.

OBJECTIVES: We conducted a collaborative cohort study to evaluate the predictive power of microvolt T-wave alternans (TWA) in patients with preserved left ventricular ejection fraction (LVEF) after myocardial infarction (MI). BACKGROUND: There is little information available about the prognostic value of risk stratification markers in this population. Although these patients have a relatively good prognosis, identifying high-risk patients is important in clinical practice. METHODS: This study enrolled 1,041 post-MI patients with an LVEF > or =40% (average 55 +/- 10%). Microvolt TWA testing was performed 48 +/- 66 days after acute MI, and 10 other risk variables were also evaluated. The end points were prospectively defined as sudden cardiac death or life-threatening arrhythmic events. RESULTS: During a follow-up of 32 +/- 14 months, 38 patients (3.7%) died of nonarrhythmic causes and were not considered for analysis. Of the 1,003 evaluable patients, 18 (1.8%) reached an end point. Microvolt TWA was positive in 169 patients (17%), negative in 747 (74%), and indeterminate in 87 (9%). A positive microvolt TWA test, nonsustained ventricular tachycardia, and ventricular late potentials were predictors of events, and percutaneous coronary intervention decreased the risk rate. On multivariate analysis, a positive microvolt TWA test was the most significant predictor, with a hazard ratio of 19.7 (p < 0.0001). This marker had the highest sensitivity and negative predictive value for events. CONCLUSIONS: In patients with preserved cardiac function, the incidence of indeterminate results of microvolt TWA is low, and a positive test result is associated with arrhythmic events. Microvolt TWA could be used for risk stratification in this low-risk population.

Microbial responses using denaturing gradient gel electrophoresis to oil and chemical dispersant in enclosed ecosystems.

Microbial responses to the addition of oil with or without a chemical dispersant were examined in mesocosm and microcosm experiments by using denaturing gradient gel electrophoresis of bacterial ribosomal DNA and direct cell counting. When a water-soluble fraction of oil was added to seawater, increases in cell density were observed in the first 24h, followed by a decrease in abundance and a change in bacterial species composition. After addition of an oil-dispersant mixture, increases in cell density and changes in community structure coincided, and the amount of bacteria remained high. These phenomena also occurred in response to addition of only dispersant. Our results suggest that the chemical dispersant may be used as a nutrient source by some bacterial groups and may directly or indirectly prevent the growth of other bacterial groups.

Identification of functional block line in atrial flutter using three-dimensional intracardiac echocardiography.

The crista terminalis (CT) is reportedly a critical barrier for maintaining typical atrial flutter (AFL), but recent observations have suggested the presence of posteromedial functional block, as well as crista conduction. Therefore, this study was designed to identify the correlation between the posterior boundary of AFL and anatomical architecture in the human right atrium (RA) using 3-dimensional (D) intracardiac echocardiography (ICE). In 11 patients with AFL (typical 9, reverse typical 2), mapping with a 10-pole (n=5) or 32-pole (n=6) catheter was performed during AFL. ICE was used to determine the catheter's position relative to the intra-atrial structures. In all patients, double potentials were recorded at the posteromedial RA and the catheter positions were recognized as posterior to the CT by 3-D ICE. Double potentials were not recorded on the CT, and the activation sequence revealed a craniocaudal direction in the 9 patients with typical AFL and caudocranial direction in the 2 patients with reverse typical AFL. These findings demonstrate that the posterior boundary of the AFL circuit is in the sinus venosa region posterior to the CT, which may provide an important insight into the mechanism of maintaining AFL.

Study of the effect of water-soluble fractions of heavy-oil on coastal marine organisms using enclosed ecosystems, mesocosms.

Mesocosm facilities composed of 4 experimental and 2 reservoir tanks (1.5 m in diameter, 3.0 m in depth and 5 tons in capacity) made of FRP plastics, were constructed in the concrete fish rearing pond in the Fisheries Laboratory, The University of Tokyo. The water-soluble fraction of Rank A heavy residual oil was formed by mixing 500 g of the oil with 10 l of seawater, which was introduced to the 5000 l-capacity tanks. Experimental Run 4 was conducted from May 31 to June 7, 2000. Oil concentrations in the tanks were 4.5 microg/l called LOW, and 13.5 microg/l, called HIGH tank. Bacterial growth rates very quickly accelerated in the HIGH tank just after the loading of oil which corresponded with a high increase of bacterial cells in the same tank after 2 days. Later, bacterial numbers in HIGH tank rapidly decreased, corresponding with the rapid increase of heterotrophic nano-flagellates and virus numbers on the same day. Sediment traps were deployed at the bottom of the experimental tanks, and were periodically retrieved. These samples were observed both under light microscope and epi-fluorescent microscope with UV-excitation. It was observed that the main components of the vertical flux were amorphous suspended matter, mostly originating from dead phytoplankton and living diatoms. It was further observed from the pictures that vertical transport of oil emulsions were probably conducted after adsorption to amorphous suspended matter and living diatoms, and were settling in the sediment traps at the bottom of the tanks. This means that the main force which drives the soluble fraction of oil into bottom sediment would be vertical flux of such amorphous suspended particles and phytoplankton. Further incubation of the samples revealed that the oil emulsions were degraded by the activity of autochtonous bacteria in the sediment in aerobic condition.

Study on the fate of petroleum-derived polycyclic aromatic hydrocarbons (PAHs) and the effect of chemical dispersant using an enclosed ecosystem, mesocosm.

Polycyclic Aromatic Hydrocarbons (PAHs) are one of the components found in oil and are of interest because some are toxic. We studied the environmental fate of PAHs and the effects of chemical dispersants using experimental 500 l mesocosm tanks that mimic natural ecosystems. The tanks were filled with seawater spiked with the water-soluble fraction of heavy residual oil. Water samples and settling particles in the tanks were collected periodically and 38 PAH compounds were analyzed by gas chromatography-mass spectrometry (GC-MS). Low molecular weight (LMW) PAHs with less than three benzene rings disappeared rapidly, mostly within 2 days. On the other hand, high molecular weight (HMW) PAHs with more than four benzene rings remained in the water column for a longer time, up to 9 days. Also, significant portions (10-94%) of HMW PAHs settled to the bottom and were caught in the sediment trap. The addition of chemical dispersant accelerated dissolution and biodegradation of PAHs, especially HMW PAHs. The dispersant amplified the amounts of PAHs found in the water column. The amplification was the greater for the more hydrophobic PAHs, with an enrichment factor of up to six times. The increased PAHs resulting from dispersant use overwhelmed the normal degradation and, as a result, higher concentrations of PAHs were observed in water column throughout the experimental period. We conclude that the addition of the dispersant could increase the concentration of water column PAHs and thus increase the exposure and potential toxicity for organisms in the natural environment. By making more hydrocarbon material available to the water column, the application of dispersant reduced the settling of PAHs. For the tank with dispersant, only 6% of chrysene initially introduced was detected in the sediment trap whereas 70% was found in the trap in the tank without dispersant.