Differences In Peak Time Research Articles

Evaluation of strain indexes and prognosis of patients with cardiac amyloidosis with preserved LVEF by three-dimensional speckle tracking imaging

Objective: To evaluate the patients with Cardiac amyloidosis (CA) and Hypertrophic cardiomyopathy (HCM) by using the strain indexes of three-dimensional speckle tracking imaging(3D-STI) technique, and to evaluate the prognosis. Methods: A total of 32 patients with pathologically confirmed cardiac amyloidosis and 34 patients with hypertrophic cardiomyopathy and 16 normal controls were enrolled from the First Affiliated Hospital of Zhejiang University College of Medicine from June, 2013 to January, 2018.The color Doppler echocardiography and three-dimensional speckle tracking echocardiography were used to measure strain indexes of each group, and the Logistic regression equation was used to analyze the index differences.The cut-off values were analyzed using the Receiver Operating Characteristic (ROC), and Kaplan-Meier and Cox were used for survival regression analysis. Results: The globe radial strain (GRS) (16%±7% vs 23%±9%), left ventricular wall peak time difference (PSD) (52 ms±17 ms vs 77 ms±25 ms), Sokolow-Lyon index (20 mm±6 mm vs 34 mm±14 mm) were significantly different between cardiac amyloidosis group and hypertrophic cardiomyopathy group by 3D-STI, which had high sensitivity and specificity by Logistic regression analysis.The area under the ROC curve of GRS was 0.725, PSD was 0.812, Sokolow-Lyon index was 0.832.In addition, the area strain and atrial septal thickness were significant prognostic factors according to survival regression analysis. Conclusions: For the differential diagnosis of cardiac amyloidosis with preserved LVEF, unlike echocardiographic parameters, the 3D-STI strain indicators could be used to differentiate cardiac amyloidosis from hypertrophic cardiomyopathy, reflecting obvious diagnostic advantages.When combined with area strain and atrial septal thickness, 3D-STI strain indicators could be used to predict the survival prognosis, which are important in clinical practice.

Waveforms of molecular oscillations reveal circadian timekeeping mechanisms

Circadian clocks play a pivotal role in orchestrating numerous physiological and developmental events. Waveform shapes of the oscillations of protein abundances can be informative about the underlying biochemical processes of circadian clocks. We derive a mathematical framework where waveforms do reveal hidden biochemical mechanisms of circadian timekeeping. We find that the cost of synthesizing proteins with particular waveforms can be substantially reduced by rhythmic protein half-lives over time, as supported by previous plant and mammalian data, as well as our own seedling experiment. We also find that previously enigmatic, cyclic expression of positive arm components within the mammalian and insect clocks allows both a broad range of peak time differences between protein waveforms and the symmetries of the waveforms about the peak times. Such various peak-time differences may facilitate tissue-specific or developmental stage-specific multicellular processes. Our waveform-guided approach can be extended to various biological oscillators, including cell-cycle and synthetic genetic oscillators.

Identifying trippers and non-trippers based on knee kinematics during obstacle-free walking

Trips are a major cause of falls. Sagittal-plane kinematics affect clearance between the foot and obstacles, however, it is unclear which kinematic measures during obstacle-free walking are associated with avoiding a trip when encountering an obstacle. The purpose of this study was to determine kinematic factors during obstacle-free walking that are related to obstacle avoidance ability. It was expected that successful obstacle avoidance would be associated with greater peak flexion/dorsiflexion and range of motion (ROM), and differences in timing of peak flexion/dorsiflexion during swing of obstacle-free walking for the hip, knee and ankle. Three-dimensional kinematics were recorded as 35 participants (young adults age 18–45 (N = 10), older adults age 65+ without a history of falls (N = 10), older adults age 65+ who had fallen in the last six months (N = 10), and individuals who had experienced a stroke more than six months earlier (N = 5)) walked on a treadmill, under obstacle-free walking conditions with kinematic features calculated for each stride. A separate obstacle avoidance task identified trippers (multiple obstacle contact) and non-trippers. Linear discriminant analysis with sequential feature selection classified trippers and non-trippers based on kinematics during obstacle-free walking. Differences in classification performance and selected features (knee ROM and timing of peak knee flexion during swing) were evaluated between trippers and non-trippers. Non-trippers had greater knee ROM (P = .001). There was no significant difference in classification performance (P = .193). Individuals with reduced knee ROM during obstacle-free walking may have greater difficulty avoiding obstacles.

Age-associated changes in the equine flash visual evoked potential.

To investigate age-associated changes of flash visual evoked potentials (FVEPs) in sedated horses. Twenty-eight clinically healthy Standardbred Warmblooded trotters, aged 36hours to 28years. Light-adapted FVEPs and FERGs were recorded (An-vision RETIport, Roland-consult, Germany) in response to flash stimuli. Sedation was obtained using alpha-2-agonists intravenously. Akinesia of the eyelids was induced and pupils were dilated. Reproducible FVEPs and FERGs were readily recorded from all foals and horses. The FVEP waveform included up to four positive components (P1-P5) and two negative components (N1 and N2) and FVEP waveform morphology was similar across all age groups. Some differences in peak times and amplitudes associated with increasing age were observed. FVEP amplitudes recorded from newborn foals were well above the amplitudes observed in normal adult horses and FVEP peak times were somewhat shorter. In adult horses, a significant increase in P4 peak time and a gradual decrease in amplitudes, mainly for N2P4, were seen across the life-span. The overall equine FVEP waveform was similar across the normal life-span of the horse in our cross-sectional study. We found that the visual system of the foal seems to be well developed already at birth. Furthermore, our results showed a decrease in amplitudes and increase in some peak times with increasing age. We recommend that age-matched controls should be used when evaluating foals and young horses in clinical practice, whereas horses over the age of three years can be compared to other adult horses.

Plantar Pressure Measurements and Geometric Analysis of Patients With and Without Morton's Neuroma.

The purpose of this research was to see if there were any differences in peak pressure, contact time, pressure-time integrals, and geometric variables such as forefoot width, foot length, coefficient of spreading, and arch index between subjects with Morton's neuroma (MN) and control subjects. Dynamic peak plantar pressure, contact time, pressure-time integral, and geometric data were extracted using the EMED-X platform in 52 subjects with MN and 31 control subjects. Differences in peak pressure, contact time, pressure-time integral, and geometric data between participants with and those without MN were determined using independent-samples t tests. There were no significant differences in age, weight, height, and body mass index between patients with MN and control subjects. There were no significant differences in the peak pressures of all masked areas and pressure-time integrals under metatarsal 2 to 4 heads between patients with MN and control subjects. In addition, no significant differences were observed between patients with MN and control subjects in geometric measurements of forefoot length, width, coefficient of spreading, foot progression angle, and arch index. No relationship was found in this study between peak pressure, contact time, and pressure-time integral under the metatarsal heads, forefoot width, foot length, coefficient of spreading, and foot progression angle in a symptomatic MN group compared with a control group. The need to perform osteotomies to treat MN not associated with other lesser metatarsal phalangeal joint pathologies is questionable. Level III, Case-Control Study.

Visualization of Arc promoter-driven neuronal activity by magnetic resonance imaging

Visualization of direct neuronal activity to understand brain function is one of the most important challenges in neuroscience. We have previously demonstrated that in vivo and in vitro gene expression of the ferritin reporter system could be detected by magnetic resonance imaging (MRI). In addition, increased neuronal activity induces Arc, an immediate early gene, and insertion of a destabilized fluorescent reporter dVenus under Arc promoter control has been used for monitoring neuronal activities in the brain by optical imaging. In this study, to visualize Arc promoter-driven neuronal activities directly, we generated transgenic mice and cell lines that express a destabilized fusion reporter ferritin-mKate2 under Arc promoter control. When transgenic mice and cell lines were treated with pilocarpine, a non-selective muscarinic agonist, an increase in T2-weighted image signal was successfully found in neuronal cells. There was a difference in peak time between MRI and fluorescence imaging, which might result from the binding process of iron with ferritin. Visualization of Arc promoter-driven neuronal activity is essential to understand neural mechanisms underlying cognitive processes and complex behaviors, and could be a useful tool for therapeutic approaches in the brain by MRI.

CEDAR‐GEM Challenge for Systematic Assessment of Ionosphere/Thermosphere Models in Predicting TEC During the 2006 December Storm Event

AbstractIn order to assess current modeling capability of reproducing storm impacts on total electron content (TEC), we considered quantities such as TEC, TEC changes compared to quiet time values, and the maximum value of the TEC and TEC changes during a storm. We compared the quantities obtained from ionospheric models against ground‐based GPS TEC measurements during the 2006 AGU storm event (14–15 December 2006) in the selected eight longitude sectors. We used 15 simulations obtained from eight ionospheric models, including empirical, physics‐based, coupled ionosphere‐thermosphere, and data assimilation models. To quantitatively evaluate performance of the models in TEC prediction during the storm, we calculated skill scores such as RMS error, Normalized RMS error (NRMSE), ratio of the modeled to observed maximum increase (Yield), and the difference between the modeled peak time and observed peak time. Furthermore, to investigate latitudinal dependence of the performance of the models, the skill scores were calculated for five latitude regions. Our study shows that RMSE of TEC and TEC changes of the model simulations range from about 3 TECU (total electron content unit, 1 TECU = 1016el m−2) (in high latitudes) to about 13 TECU (in low latitudes), which is larger than latitudinal average GPS TEC error of about 2 TECU. Most model simulations predict TEC better than TEC changes in terms of NRMSE and the difference in peak time, while the opposite holds true in terms of Yield. Model performance strongly depends on the quantities considered, the type of metrics used, and the latitude considered.

Optimal Region of Interest Location of Test Bolus Technique in Extra Cranial Carotid Contrast Enhanced Magnetic Resonance Angiography

This study is aimed to optimize a location of region of interest (ROI) in test bolus carotid contrast enhanced magnetic resonance angiography (CE-MRA) at 3.0T. A total of consecutive 270 patients with no cardiovascular and vessel diseases were selected. Patients underwent elliptical centric 3D CE-MRA with the test bolus technique to identify the individual arterial arrival time. Quantitative measurements were performed by drawing ROIs of 25 ㎟ and signal intensities (SI) were measured in the center of common carotid artery (CCA), internal carotid artery (ICA) and aortic arch (AA). As a result, ROIs located within AA showed a significantly clarified arterial peak and over three times increased SI, while no significant arterial peak time differences were observed compared to ROIs located within CCA. In conclusion, it was demonstrated that the aortic arch is the optimal position to locate ROI in test bolus images of the carotid CE-MRA.

The correlation between HER-2 expression and the CEUS and ARFI characteristics of breast cancer.

ObjectiveThe purpose of the present study was to explore the correlation between the contrast-enhanced ultrasound (CEUS) and acoustic radiation force impulse (ARFI) characteristics of breast cancers and the expression of human epidermal growth factor receptor 2 (HER-2).MethodsHER-2 expression levels in the tumor masses of 167 clearly diagnosed cases of breast cancer were measured and analyzed. The enhancement features and time intensity curve (TIC) of CEUS and virtual touch tissue imaging (VTI) and virtual touch tissue quantification (VTQ) technology of ARFI were employed to analyze the relationship between HER-2 expression and the CEUS and ARFI characteristics of breast cancer.Results(1) Statistically significant differences in the distribution of the contrast agent, perforator blood flow, the overranging phenomenon and perfusion defects between the study groups with different HER-2 expression levels (P < 0.05) were observed on CEUS. In addition, statistically significant differences in the TIC peak time (PT), slope of the ascending branch (K) and area under the curve (AUC) were found in the groups expressing different levels of HER-2 (P < 0.05). In contrast, the degree of contrast agent enhancement and TIC peak intensity (PI) were found to be independent of the expression status of HER-2, as they were not statistically significant (P > 0.05). (2) Statistically significant differences in the VTQ results between the groups with different HER-2 expression levels were found (P < 0.05). However, no statistically significant differences in VTI image characteristics were detected between the groups expressing different levels of HER-2 (P > 0.05).ConclusionA correlation was found between the CEUS and ARFI characteristics of breast cancer and HER-2 expression levels. This correlation was principally reflected in perfusion defects, perforator blood flow, PI, PT, K and VTQ.

Digital core based transmitted ultrasonic wave simulation and velocity accuracy analysis

Transmitted ultrasonic wave simulation (TUWS) in a digital core is one of the important elements of digital rock physics and is used to study wave propagation in porous cores and calculate equivalent velocity. When simulating wave propagates in a 3D digital core, two additional layers are attached to its two surfaces vertical to the wave-direction and one planar wave source and two receiver-arrays are properly installed. After source excitation, the two receivers then record incident and transmitted waves of the digital rock. Wave propagating velocity, which is the velocity of the digital core, is computed by the picked peak-time difference between the two recorded waves. To evaluate the accuracy of TUWS, a digital core is fully saturated with gas, oil, and water to calculate the corresponding velocities. The velocities increase with decreasing wave frequencies in the simulation frequency band, and this is considered to be the result of scattering. When the pore fluids are varied from gas to oil and finally to water, the velocity-variation characteristics between the different frequencies are similar, thereby approximately following the variation law of velocities obtained from linear elastic statics simulation (LESS), although their absolute values are different. However, LESS has been widely used. The results of this paper show that the transmission ultrasonic simulation has high relative precision.

Influence of the Mississippi River on Pseudo-nitzschia spp. Abundance and Toxicity in Louisiana Coastal Waters

The presence of domoic acid (DA) toxin from multiple species of Pseudo-nitzschia is a concern in the highly productive food webs of the northern Gulf of Mexico. We documented the Pseudo-nitzschia presence, abundance, blooms, and toxicity over three years along a transect ∼100 km west of the Mississippi River Delta on the continental shelf. Pseudo-nitzschia were present throughout the year and occurred in high abundances (>104 cells l−1) in the early spring months during high Mississippi River (MSR) flow (∼20,000 m3 s−1) but were most abundant (>106 cells l−1) when MSR discharge was relatively lower among the spring months. A high particulate toxin production (maximum reaching 13 μg DA l−1) was associated with the high cell abundances and exceeded, by an order of magnitude, prior reports of particulate DA concentrations in Louisiana coastal waters. Differences in Pseudo-nitzschia peak times and its toxicity were correlated mainly with the timing and magnitude of MSR discharge and changes in associated parameters such as nutrient stoichiometry and salinity. A negative relationship between high MSR discharge and Pseudo-nitzschia and particulate DA concentrations was documented. These riverine dynamics have the potential to influence DA contamination in pelagic and benthic food webs in the coastal waters of the northern Gulf of Mexico.

Value of annular plane systolic excursion difference in evaluation of heart systolic function of normal fetuses in the second and late trimester with echocardiography

Objective To obtain the annular plane systolic excursion difference (APSED) of fetuses in second and late trimester by free angle M-mode(FAM) and tissue motion of annular displacement(TMAD) in order to assess the fetal ventricular function. Methods The mitral annular plane systolic excursion(MAPSE) and tricuspid annular plane systolic excursion(TAPSE) of four hundred and fifty five normal fetuses from 20 to 41 weeks were measured by FAM echocardiography, and the difference between them were calculated. Early diastolic velocities (Em) of the mitral annular and early diastolic velocities (Em') of the tricuspid annular were estimated by pulsed-wave tissue Doppler imaging(TDI), meanwhile systolic velocities (Sm) of the mitral annular and systolic velocities (Sm') of the tricuspid annular were also estimated by TDI. Fifty normal fetuses in the second and late trimester were choosed randomly, two-dimension imaging was obtained at the apical four-chamber view, then mitral annular plane and tricuspid annular plane displacement curve were acquired at the same time by using off-line QLab 8.1 software, and the differences in the peak time between them were compared. The trace of annular displacement were recorded by color tissue tracking technology. Results There was a significant difference between FAM-TAPSE and FAM-MAPSE in different gestational weeks (P 0.05). Conclusions The APSED existed in the second and late trimester continually. It was considering associated with fetal ventricular torsion. As the growth of gestational weeks, the increase of APSED reflected the enhanced reserve capacity of the fetal ventricular torsion. APSED can reflect the longitudinal motion and torsion movement of fetal ventricle quantitatively, and can be used as a new index to assess the fetal cardiac function. Key words: Echocardiography; Fetal heart; Ventricular function; Tissue motion of annular displacement; Annular plane systolic excursion difference

Metformin Does Not Suppress Serum Thyrotropin by Increasing Levothyroxine Absorption.

Levothyroxine (LT4) absorption is affected by concomitant ingestion of certain minerals, medications, and foods. It has been hypothesized that metformin may suppress serum thyrotropin (TSH) concentrations by enhancing LT4 absorption or by directly affecting the hypothalamic-pituitary axis. This study examined the effect of metformin ingestion on LT4 absorption, as assessed by serum total thyroxine (TT4) concentrations. A modified Food and Drug Administration LT4 bioequivalence protocol was applied to healthy, metformin-naïve, euthyroid adult volunteers. Following an overnight fast, 600 μg LT4 was administered orally. Serum TT4 concentrations were measured at baseline and at 0.5, 1, 1.5, 2, 4, and 6 h following LT4 administration. Measurements were performed before and after one week of metformin ingestion (850 mg three times daily). Peak serum TT4 concentrations, time to peak TT4 concentrations, and area under the concentration-time curve (AUC) were calculated. Twenty-six subjects (54% men, 27% white, age 33 ± 10 years) were studied. There were no significant differences in peak serum TT4 concentrations (p = 0.13) and time to peak TT4 concentrations (p = 0.19) before and after one week of metformin use. A trend toward reduced TT4 AUC was observed after metformin ingestion (pre-metformin 3893 ± 568 μg/dL-min, post-metformin 3765 ± 588 μg/dL-min, p = 0.09). LT4 absorption is unchanged by concomitant metformin ingestion. Mechanisms other than increased LT4 absorption may be responsible for the suppressed TSH concentrations observed in patients ingesting both drugs.

The Influence of Aconitum carmichaelii Debx. on the Pharmacokinetic Characteristics of Main Components in Rheum palmatum L.

Rhei Radix et Rhizoma was one of the commonly used traditional Chinese medicines, and the compatibility of Rhei Radix et Rhizoma and Aconiti Lateralis Radix Praeparata was the basic herb pair applied in many Chinese traditional prescription. Rhubarb anthraquinones were the main bioactive materials of Rhei Radix et Rhizoma. To elucidate the compatibility of Rhei Radix et Rhizoma and Aconiti Lateralis Radix Praeparata, the pharmacokinetics of rhubarb anthraquinones as the main marker constituents were investigated. In the present study, pharmacokinetic differences of rhubarb anthraquinones were detected after oral administration of extract of Rheum palmatum L. and compatibility with Aconitum carmichaelii Debx. After oral administration, no difference of peak time can be found for anthraquinones between rhubarb group and compatibility group. But Cmax and area under the curve of aloe-emodin, emodin and chrysophanol in compatibility group were significantly higher than that in rhubarb group. Although the Cmax of rhein in compatibility group was much lower than that in rhubarb group, the area under the curve value was similar in two groups. The clearance and t1/2 of rhubarb anthraquinone were also changed after compatibility. The change of pharmacokinetics characteristics of rhubarb anthraquinone after compatibility may be caused by the drug-drug interaction medicated by chemical reaction and cytochromes P450.

Does Hemoglobin S in Sickle Cell Trait and Sickle Cell Anemia Induce Higher Hemostatic Potential?

Introduction: Previous studies reported that patients with sickle cell disease (SCD) present with alterations of several factors involved in the coagulation system but also that global hemostatic potential parameters are enhanced in children with SCD suggesting hypercoagulability even at steady state. Such modifications have rarely been studied in adult SCD cohorts or individuals with a sickle cell trait (AS). On the other hand, observation of clinical events suggests that SCD adults patients are at higher risk of thrombosis, while those AS are at higher risk of deep venous and pulmonary thrombosis as well as sudden death after intense physical activity. The aim of our study was to characterise the global haemostatic potential of SS and AS adults.Materials and Methods: Three groups were studied and consisted in 31 controls (group AA), 26 sickle cell trait (group AS) and 29 SCD patients (group SS) at steady state. Hemoglobin phenotype was assessed by combination of cation-exchange high performance chromatography (beta-thal short program BioRad) and capillary electrophoresis (Capillarys systems Sebia Benelux). We used the Calibrated Automated Thrombogram® to measure thrombin generation (TG) on platelet poor plasma (PPP) processed, aliquoted and frozen until needed for further testing in batches. TG was triggered using 1 pM tissue factor (TF) and 4µM phospholipids (PL) in two different conditions: with and without addition of thrombomodulin (TM). The interquartile range for several monitored parameters, namely lag time (min), time to peak (min), velocity index (nM/min), endogeneous thrombin potential (ETP, nM.min) and peak (nM) was compared between the 3 groups using Kruskall-Wallis and Dunn’s multiple group comparison tests. Protein C activity (PC), free protein S (PS), factor VIII (FVIII), LDH, Thrombin anti-thrombin complex (TAT) and ultrasensitive CRP (CRP us) were also measured in parallel. Informed written consent was obtained from each subject prior to sampling; the study received approval from the local ethics committee.Results: Without TM, there was a significant difference in peak, velocity index and lag time between the 3 groups (p<0.0001). Highest peak and velocity index, intermediate results and the lowest results were observed for SS, AS and AA groups, respectively. The lowest lag time was obtained for the SS group followed by the AS and AA groups (P< 0.0001).The addition of TM didn’t modify peak, velocity and lag time results. In contrast, ETP was higher for SS and AS group as compared with AA in the presence of TM (p<0.05). PC and PS were lower for the SS group as compared with AA group (p<0.01); PC was intermediate in the AS group. FVIII, CRP us, LDH and TAT were higher for SS as compared with AA (p<0.001).Summary: In this preliminary study we showed that global hemostatic parameters were enhanced in adult SCD patients at steady state. This observation could be related to both a deficiency of the anticoagulant PC pathway and an inflammatory state. Even though we could not highlight hypercoagulability using individual parameters for AS individuals, they showed intermediate profile in global CAT test. In this later group, clinical impact should be investigated in a prospective way. Correlation with HbS level is currently ongoing. DisclosuresNo relevant conflicts of interest to declare.

English

Starch was extracted from three different plantain (Musa paradisiaca) cultivars: agbagba, cadaba and French horn, and the physico-chemical and pasting properties of the starch were investigated. The percentage starch yield ranges from 6.67 (cadaba) to 15.00% (French horn). pH values fall between 4.46 to 5.50 with the highest pH occurring in cadaba (5.50). A higher moisture content of 13.15% was observed in French horn which was significantly different (p ≥ 0.05) from 11.56% recorded in Agbagba. The swelling power showed no significant difference (p ≥ 0.05) between the cultivars studied. However, Agbagba cultivar had higher starch solubility (7.49%) as compared to other cultivars. Although, a higher amylose (%) was observed in three cultivars (29.96 - 30.91%), it showed no significant difference (p ≥ 0.05) which also affected the amylopectin. The peak viscosity and trough was higher in starches from French horn (163.17 and 135.00 RVU, respectively) with the lowest breakdown viscosity of 28.17 RVU. Pasting temperature was observed to be higher in Agbagba (94.75°C) with a corresponding peak time of 5.58 min; however there was no significant difference (p ≥ 0.05) in peak time (which is an indication of cooking time) between the cultivars studied. Key words: Plantain starch, cultivars, pasting properties, physico-chemical properties.

ADCP 표층유속 자료처리방법 개선을 통한 영산강 하구 표층 방류수 이류속도 산정

It has been customary to exclude top 10-20% of velocity profiles in the Acoustic Doppler Current Profiler (ADCP) measurement due to side lobe effects at the boundary. To better understand the mixing in the Yeongsan estuary, the freshwater advection speed (FAS) was recovered from highly contaminated ADCP data near the surface. The velocity profiles were measured by using ADCP at two stations in the Yeongsan estuary during August 2011: one was located in front of the Yeongsan estuarine dam and the other was deployed near Goha Island. The FAS was recovered from the ADCP data set by applying rigorous post-processing methods and compared with the sediment advection speed (SAS). The SAS was determined by the peak time difference of suspended sediment concentration between two stations in the channel, divided by the distance of two stations. The FAS and the SAS showed very similar value when the freshwater discharge was greater than ton and the SAS was a bit greater when the freshwater discharge was smaller. Since the FAS was on average about 0.8 m/s greater than the velocity at 0.8 of water depth from the bottom, the net discharge, estimated with recovered FAS and integrated over water depth and tidal cycle, was directed seaward during the high discharge contrary to the onshore direction of the net discharge estimated with 0.8 of water depth from the bottom. Moreover, the velocity shear and Richardson number changed when the FAS was used. Thus, the importance of the true FAS is appreciated in the investigation of the surface layer stability. If currents, temperature and salinity were observed for longer time in the future, it could be possible to more accurately understand the formation and decay of stratification as well as the suspended sediment transport processes.

Interocular Amplitude and Latency Differences of Pattern ERG and Pattern VEP Parameters

To determine the normal interocular differences in amplitudes and peak times of the pattern electroretinograms (PERGs) and pattern visual evoked potentials (PVEPs) and to investigate whether the PERG and PVEP parameters correspond in lateral dominance or whether the eye-side distributions of the functional parameters are similar. The PERGs and PVEPs were recorded in healthy subjects (N = 77) according to the standards of the International Society for Clinical Electrophysiology of Vision, with the modification of the check size of the PERG to 0.5 degrees. This allows stimulation of the macular ganglion cells and their corresponding visual pathways in healthy subjects. Comparison of the averaged higher and lower response amplitudes and the shorter and longer response peak times showed significant differences (p < 0.001) in both the PERG and the PVEP parameters (median [5 to 95%]): the P50 (1.92% [0 to 5.48%]) and N95 (2.06% [0 to 13.95%]) peak times and the P50 (11.82% [1.32 to 29.93%) and N95 (9.45% [1.17 to 30.38%]) amplitudes of the PERGs and the P100 (1.04% [0 to 4.15%]) and N135 (1.96% [0 to 12.36%]) peak times and the P100 (9.86% [1.26 to 29.76%]) and N135 (11.19% [1.18 to 29.99%]) amplitudes of the PVEPs. No significant correlation was found concerning the eye dominance of the PERG and PVEP parameters. Our results reveal a significant interocular difference on PERG and PVEP recording, but this could not be ascribed to the anatomy of the retina and related visual pathways. If the difference between the eyes is not taken into account, misinterpretation may occur in a pathological process.

Abstract T MP36: Indocyanine Green Videoangiography for Assessment of Postoperative Hyperperfusion in Moyamoya Disease

Introduction: Postoperative cerebral hyperperfusion (HP) is a notable complication that occurs more frequently in moyamoya disease (MMD) than in atherosclerosis of unknown etiology. This study aimed to clarify the characteristics of intraoperative indocyanine green (ICG) videoangiography in MMD and atherosclerotic disease in terms of postoperative HP. Methods: This prospective study included 47 patients with 60 sides that underwent superior temporal artery (STA)-middle cerebral artery (MCA) single bypass. ICG videoangiography was performed after revascularization. The ICG time intensity curve was recorded in the STA, proximal MCA, distal MCA, and superficial Sylvian vein, and the angiographic differences among adult MMD, pediatric MMD, and atherosclerosis were analyzed. Results: Twenty two patients (27 sides) had adult MMD, 14 patients (22 sides) had pediatric MMD, and 11 patients (11 sides) had atherosclerosis. Postoperative HP was significantly higher in adult MMD (40.7%) than in pediatric MMD (18.2%) and atherosclerosis (0%). Adult MMD with HP was associated with a longer ICG peak time (P&lt;0.001). There was no significant difference in ICG peak time among presentations in MMD, and no correlation between ICG peak time and preoperative hemodynamic parameters. The ratio of the vessel caliber was also higher in adult MMD with HP (P&lt;0.001). Conclusions: ICG videoangiography provides different characteristics of bypass flow among adult MMD, pediatric MMD, and atherosclerosis. Poor distribution and run-off of blood flow from the STA might contribute to postoperative HP in MMD. The occurrence of postoperative HP in MMD could depend on two factors: host STA size and recipient MCA integrity.

Phase Difference Between Chronotypes in Self-Reported Maximum of Alertness Rhythm

An objective physiological predictor of self-reported chronotypological differences in circadian timing of alertness peak (&gt; 5 hr) has not been yet identified. Our goals were to establish external validity of such a predictor, and to explain the observations of inequality of chronotypological differences in alertness peak and bed/rising times (&gt; 5 and &lt; 3 hr, respectively). The resting electroencephalogram was recorded at 3-hr intervals during 24-hr sustained wakefulness of 130 healthy participants. An objective index (alpha-theta power difference) was calculated for the eyes closed section of each record. The time course of subjective alertness-sleepiness was compared with the time course of the objective index and simulated with a rhythmostatic model. External validity of the objective predictor of chronotypological differences was supported by the resemblance between the time courses, and the simulations revealed contribution of other than circadian phase parameters of the chronoregulatory processes to the appearance of &gt; 5-hr chronotypological difference between alertness peaks.