Two common issues in synchronized multimodal recordings with EEG: Jitter and latency

Multimodal recording using electroencephalogram (EEG) and other biological signals (e.g., muscle activities, eye movement, pupil diameters, or body kinematics data) is ubiquitous in human neuroscience research. However, the precise time alignment of multiple data from heterogeneous sources (i.e., devices) is often arduous due to variable recording parameters of commercially available research devices and complex experimental setups. In this review, we introduced the versatility of a Lab Streaming Layer (LSL)-based application that can overcome two common issues in measuring multimodal data: jitter and latency. We discussed the issues of jitter and latency in multimodal recordings and the benefits of time-synchronization when recording with multiple devices. In addition, a computer simulation was performed to highlight how the millisecond-order jitter readily affects the signal-to-noise ratio of the electrophysiological outcome. Together, we argue that the LSL-based system can be used for research requiring precise time-alignment of datasets. Studies that detect stimulus-induced transient neural responses or test hypotheses regarding temporal relationships of different functional aspects with multimodal data would benefit most from LSL-based systems.

Between-Tactor Display Using Dynamic Tactile Stimuli for Directional Cueing in Vibrating Environments

Torso-worn vibrotactile devices have been used in many studies on directional cueing and navigation in environments where visual feedback is limited. These devices aim to indicate directions with high resolution while using the smallest possible number of vibration motors (tactors). Resolution can be increased using between-tactor displays, but their performance in vibrating environments (e.g., a helicopter) are unknown. This study proposes a between-tactor display using dynamic stimuli and verifies its effectiveness when the user sits in a vibrating chair. We developed a waist belt device that displays 12 directions using 6 tactors. Static stimuli display virtual (between-tactor) locations by constantly vibrating two adjacent tactors equally, whereas dynamic stimuli move the virtual vibration position back and forth between tactors. We performed two studies in which participants felt tactile stimuli and used a joystick to move a cursor on a screen to a target in the perceived direction. Direction recognition accuracy and task completion time were measured under combined conditions of two belt orientations (tactor alignments), with and without chair vibration, and with and without audio white noise to mask tactor sound. In all conditions, dynamic stimuli increased recognition accuracy while maintaining task completion time compared to static stimuli.

Compensatory gait mechanics in person with multiple toe amputation: A single case report

This case highlights the biomechanical influence of toe amputation on contralateral limb force elevation, possibly through reduced ipsilateral plantar flexor torque production. These findings provide insight into toe amputation-related compensatory gait mechanics with greater inter-limb asymmetry, which may increase the risk of musculoskeletal comorbidities, including osteoarthritis in contralateral limb.

Antagonistic interactions between odorants alter human odor perception

The olfactory system uses hundreds of odorant receptors (ORs), the largest group of the G-protein-coupled receptor (GPCR) superfamily, to detect a vast array of odorants. Each OR is activated by specific odorous ligands, and like other GPCRs, antagonism can block activation of ORs. Recent studies suggest that odorant antagonisms in mixtures influence olfactory neuron activities, but it is unclear how this affects perception of odor mixtures. In this study, we identified a set of human ORs activated by methanethiol and hydrogen sulfide, two potent volatile sulfur malodors, through large-scale heterologous expression. Screening odorants that block OR activation in heterologous cells identified a set of antagonists, including β-ionone. Sensory evaluation in humans revealed that β-ionone reduced the odor intensity and unpleasantness of methanethiol. Additionally, suppression was not observed when methanethiol and β-ionone were introduced simultaneously to different nostrils. Our study supports the hypothesis that odor sensation is altered through antagonistic interactions at the OR level.

Hemoglobin in the blood acts as a chemosensory signal via the mouse vomeronasal system

The vomeronasal system plays an essential role in sensing various environmental chemical cues. Here we show that mice exposed to blood and, consequently, hemoglobin results in the activation of vomeronasal sensory neurons expressing a specific vomeronasal G protein-coupled receptor, Vmn2r88, which is mediated by the interaction site, Gly17, on hemoglobin. The hemoglobin signal reaches the medial amygdala (MeA) in both male and female mice. However, it activates the dorsal part of ventromedial hypothalamus (VMHd) only in lactating female mice. As a result, in lactating mothers, hemoglobin enhances digging and rearing behavior. Manipulation of steroidogenic factor 1 (SF1)-expressing neurons in the VMHd is sufficient to induce the hemoglobin-mediated behaviors. Our results suggest that the oxygen-carrier hemoglobin plays a role as a chemosensory signal, eliciting behavioral responses in mice in a state-dependent fashion.

Gait analysis of patients with distal radius fracture by using a novel laser Timed Up-and-Go system

BACKGROUND

Postmenopausal women are at risk of fall and fracture with the physical decline. Distal radius fracture (DRF) is considered as the primary fragility fracture, and women with this fracture showed poor results in the usual Timed Up-and-Go (TUG) test, indicating a decline in balance and physical ability. The detailed physical characteristics of female DRF patients have not been extensively examined.

RESEARCH QUESTION

Is the novel laser TUG system able to detect and analyze the detailed gait characteristics in patients with DRF whose physical ability has tended to decline?

METHODS

In this cross-sectional case control study, the gait characteristics of 32 female patients　with DRF who had undergone surgery were evaluated at 2 weeks postoperatively with a　laser TUG system to analyze the detailed leg motion during normal TUG test.　Forty-three age- and sex-matched non-fractured women were evaluated by the laser TUG system as controls. Lifestyle and present illness were corrected at the time of TUG measurement. Detailed data during laser TUG in both groups were compared statistically, and odds ratio and thread shod of the fracture was elucidated through a　logistic regression analysis.

RESULTS

DRF patients showed slower speed and had to do more steps to complete the TUG test. Furthermore, asymmetric trajectory and significantly further distance from the marker were observed. Thirteen steps to complete the TUG test was the thread shod of DRF.

SIGNIFICANCE

Detailed gait characteristics of patients with DRF were detected by the laser TUG system. The gait decline and abnormality could be one of the reasons of consecutive fragility fracture. To prevent secondary fragility fractures, this system can be useful for screening.

Estimation of Vertical Ground Reaction Force Using Low-Cost Insole With Force Plate-Free Learning From Single Leg Stance and Walking

For the evaluation of pathological gait, a machine learning-based estimation of the vertical ground reaction force (vGRF) using a low-cost insole is proposed as an alternative to costly force plates. However, learning a model for estimation still relies on the use of force plates, which is not accessible in small clinics and individuals. Therefore, this paper presents a force plate-free learning from a single leg stance (SLS) and natural walking measured only by the insoles. This method used a linear least squares regression that fits insole measurements during SLS to body weight in order to learn a model to estimate vGRF during walking. Constraints were added to the regression so that vGRF estimates during walking were of proper magnitude, and the constraint bounds were newly defined as a linear function of stance duration. Moreover, a lower bound for the estimated vGRF in mid-stance was added to the constraints to enhance estimation accuracy. The vGRF estimated by the proposed method was compared with force platforms for 4 healthy young adults and 13 elderly adults including patients with mild osteoarthritis, knee pain, and valgus hallux. Through the experiments, the proposed learning method had a normalized root mean squared error under 10% for healthy young and elderly adults with stance durations within a certain range (600-800 ms). From these results, the validity of the proposed learning method was verified for various users requiring assessment in the field of medicine and healthcare.

Stair climbing ability in patients with early knee osteoarthritis: Defining the clinical hallmarks of early disease

BACKGROUND

A growing clinical interest has been shown towards identifying knee osteoarthritis (OA) patients at earlier stages. The early detection of knee OA may allow for more effective interventions.

RESEARCH QUESTION

The aim of this study was to determine the discriminative ability of a stair-climb test (SCT) in identifying patients with early knee OA, and to determine if descending stair time during the SCT is better than ascending stair time for the identification of these patients.

METHODS

This study was a secondary, cross-sectional analysis of baseline data from a randomized controlled trial. Adults with moderate to severe knee pain were enrolled (n = 57; mean age 58.9 years; 71.9% women). Each participant performed an 11-step SCT (11-SCT) while wearing shoes with a pressure sensor insole. A receiver operating characteristic analysis was used to examine the discriminative power of 11-SCT for identifying early knee OA (Kellgren and Lawrence grade 1). The discriminative power was also compared between the ascending and descending 11-SCT time as evaluated by the pressure sensor.

RESULTS

The 11-SCT time in patients with early knee OA was 0.55 s longer than that in those with symptomatic non-radiographic OA. A one-second increase in the 11-SCT time was significantly associated with 1.9-fold increased odds of early knee OA being present. The 11-SCT value with the best balance of sensitivity and specificity for identifying early knee OA was 8.33 s (area under the curve: 0.711). The descending time was not significantly better than the ascending time for identifying early knee OA.

SIGNIFICANCE

This study determined the time values of an 11-SCT that may be useful for identifying early knee OA patients. These preliminary findings may serve as the foundation for future studies investigating the clinical hallmarks associated with early knee OA.

Insole-Based Estimation of Vertical Ground Reaction Force Using One-Step Learning With Probabilistic Regression and Data Augmentation

An insole-based estimation of the vertical ground reaction force (vGRF) is proposed as an alternative to costly force plates for the evaluation of pathological gait. However, machine learning techniques for estimation still rely on the use of force plates. Moreover, measuring plural walking steps in order to prevent overfitting induces fall risks and physically taxes the patients. Therefore, this paper presents an accessible and efficient learning scheme for the insole-based estimation of vGRF. In this system, we employ a low-cost scale as an alternative to force plates. Then, we use Gaussian process regression (GPR) to learn a model in order to estimate vGRF without overfitting of small-sized data sets corrupted by measurement errors and noise of the devices. In addition, we propose a "one-step learning" scheme based on a probabilistic data augmentation. This approach augments actual measurements of a minimum (just one) walking step to a virtual data set for plural steps by considering their typical variability between steps. In experiments, the GPR models learned from two walking steps estimated vGRF with mean errors of 8% or under for entire/local magnitudes. Moreover, the learning from one step with probabilistic augmentation enhanced the estimation accuracy.

Effects of interaction between varus thrust and ambulatory physical activity on knee pain in individuals with knee osteoarthritis: an exploratory study with 12-month follow-up

INTRODUCTION

This study aimed to examine the interaction effect between ambulatory physical activity (PA) and varus thrust on knee pain in individuals with knee osteoarthritis (OA).

METHOD

Subjects (n = 207; mean age: 73.1 years, 71.5% women) in orthopedic clinics with diagnosed knee OA (Kellgren/Lawrence grade ≥ 1) were enrolled in this 12-month observational cohort study. Participants underwent gait observation for varus thrust assessment and pedometer-based ambulatory PA measurements at baseline and 12-month follow-up. Knee pain intensity was assessed using the Japanese Knee Osteoarthritis Measure pain subscale as a primary outcome measure. Multiple linear regression analyses were performed to evaluate ambulatory PA-thrust interaction on knee pain intensity.

RESULTS

Ninety-two subjects (mean age, 73.4 years; 68.5% women) completed the 12-month follow-up assessment. Baseline ambulatory PA-thrust interaction was significant (P = 0.017) in the cross-sectional analysis, adjusting for covariates, which yielded R² = 0.310. Subgroup analysis showed that varus thrust was significantly associated with worse knee pain in subjects walking ≥ 5000 steps/day adjusting for covariates (beta: 7.94; 95% CI: 3.82, 12.1; P < 0.001) with a higher predictive ability (R² = 0.664). In contrast, ambulatory PA-thrust interaction in the longitudinal analysis showed no significant association with knee pain changes.

CONCLUSIONS

Ambulatory PA interacted with varus thrust in the association with knee pain, as coexisting high ambulatory PA and varus thrust had the strongest association with higher knee pain. Maximal pain relief effects might be achieved when both ambulatory PA and varus thrust are treated simultaneously, rather than treating each separately.

Trunk movement asymmetry associated with pain, disability, and quadriceps strength asymmetry in individuals with knee osteoarthritis: a cross-sectional study

OBJECTIVE

This study examined 1) the clinical relevance of trunk movement asymmetry, which was evaluated using a trunk-mounted inertial measurement unit (IMU), and 2) the relationship between trunk movement asymmetry and lower limb muscle strength asymmetry in individuals with knee osteoarthritis (OA).

DESIGN

One-hundred-thirty-one participants (mean age, 74.2 years; 71.8% female; Kellgren and Lawrence [K&L] grade ≥1) underwent gait analysis at their preferred pace for IMU-based measurement of trunk movement asymmetry (harmonic ratio [HR] and improved HR). The isometric strength of quadriceps and hip abductors was evaluated using a hand-held dynamometer. Pain and disability level were evaluated using a validated self-reported questionnaire. Multiple regression analyses with covariate adjustment were performed to examine the relationship between trunk movement asymmetry (independent variable) and pain, disability level, or muscle strength asymmetry (dependent variables).

RESULTS

Individuals with severe knee OA (K&L grade ≥3) had increased trunk movement asymmetry in the medio-lateral axis compared to those with a K&L grade of 1. Increased trunk movement asymmetry was associated with a greater knee pain and disability. The increased trunk movement asymmetry was significantly associated with an increase in the asymmetry of quadriceps strength, but not with asymmetry in the strength of hip abductor.

CONCLUSION

Our findings indicate that increased medio-lateral trunk movement asymmetry may be an indicator of impairment, rather than adaptation, in individuals with knee OA. This preliminary finding warrants validation by future study. Paying close attention to medio-lateral trunk movement asymmetry may be key to our understanding of OA-related pain and disability.

Concurrent validity and measurement error of stair climb test in people with pre-radiographic to mild knee osteoarthritis

BACKGROUND

Stair climbing is the task first affected in patients with knee osteoarthritis (OA); therefore, the precise measurement of time required to climb stairs is important to identify mobility limitations, particularly in the early phase of knee OA.

RESEARCH QUESTION

This study aimed to examine the test-retest reliability, measurement error, and concurrent validity of the stopwatch-based stair-climb test (SCT) in adults with pre-radiographic to mild knee OA.

METHODS

Fifty-nine participants (mean age, 59.1 [range, 50-69] years; 72.9% female) with Kellgren and Lawrence grade ≤2 disease underwent an 11-step SCT (11-SCT) in accordance with the Osteoarthritis Research Society International recommended method while wearing pressure sensor-mounted standard shoes that is used as a gold standard procedure. Test-retest reliability, measurement errors, and the concurrent validity of the stopwatch-based 11-SCT were evaluated.

RESULTS

The test-retest reliability of the stopwatch-based 11-SCT was excellent (intra-class correlation coefficient_1,1 [ICC_1,1], 0.952; 95% confidence interval [CI], 0.560 to 0.985; p <  0.001) and the minimal detectable change₉₅ was 0.102 s. Concurrent validity was excellent (ICC_2,1: 0.957; 95% CI: 0.661 to 0.986; p <  0.001).

SIGNIFICANCE

The stopwatch-based 11-SCT had high test-retest reliability and high concurrent validity, which justify its clinical use for identifying mobility limitations in individuals with pre-radiographic to mild knee OA. A difference of 0.2 s in the stopwatch-based 11-SCT time would be considered a true difference beyond a 95% measurement error.

CYFRA 21-1 as a tumor marker for squamous cell carcinoma of the esophagus

This study assessed the clinical value of CYFRA 21-1 in comparison with squamous cell carcinoma antigen (SCC-Ag), carcinoembryonic antigen (CEA), and carbohydrate antigen 19-9 (CA19-9) in patients with esophageal squamous cell carcinoma. In 112 primary cancer patients, the diagnostic sensitivity of CYFRA 21-1 (33.9%) was superior to SCC-Ag (28.6%), CEA (12.5%), and CA19-9 (6.3%). Levels of CYFRA 21-1 were closely correlated with TNM stage and were below the cutoff value in all 21 patients with stage I disease. All 38 patients with a CYFRA 21-1 level over the cutoff value among the 80 patients who underwent esophagectomy had lymph node metastases (pNl). A correlation was found between CYFRA 21-1 levels and clinical response in serial measurements of 21 patients who received chemotherapy or chemo radiotherapy. Our findings suggest that CYFRA 21-1 is not useful for diagnosis, but that it is valuable for monitoring the efficacy of therapy.

Proton conduction in alkali metal ion-exchanged porous ionic crystals

Li⁺ in an alkali metal ion-exchanged porous ionic crystal forms a dense and extensive hydrogen-bonding network of water molecules with mobile protons leading to a high proton conductivity (>10⁻³ S cm⁻¹).

Temperature Dependence of Magnetically Active Charge Excitations in Magnetite across the Verwey Transition

We study the electronic structure of bulk single crystals and epitaxial films of Fe_{3}O_{4}. Fe 2p core level spectra show clear differences between hard x-ray (HAX) and soft x-ray photoemission spectroscopy (PES). The bulk-sensitive spectra exhibit temperature (T) dependence across the Verwey transition, which is missing in the surface-sensitive spectra. By using an extended impurity Anderson full-multiplet model-and in contrast to an earlier peak assignment-we show that the two distinct Fe species (A and B site) and the charge modulation at the B site are responsible for the newly found double peaks in the main peak above T_{V} and its T-dependent evolution. The Fe 2p HAXPES spectra show a clear magnetic circular dichroism (MCD) in the metallic phase of magnetized 100-nm-thick films. The model calculations also reproduce the MCD and identify the contributions from magnetically distinct A and B sites. Valence band HAXPES shows a finite density of states at E_{F} for the polaronic half metal with a remnant order above T_{V} and a clear gap formation below T_{V}. The results indicate that the Verwey transition is driven by changes in the strongly correlated and magnetically active B-site electronic states, consistent with resistivity and optical spectra.

[Factors influencing intraocular pressure elevation on the first postoperative day following small-incision cataract surgery--the effect of apraclonidine]

PURPOSE

To investigate the effects of apraclonidine on intraocular pressure elevation after cataract surgery and the factors associated with elevated intraocular pressure.

METHODS

A group of patients (apraclonidine group) was administered a drop of apraclonidine before and one drop after surgery, and the difference between the intraocular pressure in the apraclonidine group and the non-use group was investigated postoperatively. On the first postoperative day, multivariate analysis was performed using intraocular pressure as the objective value and other variable factors involved in the surgery as the explanatory variables.

RESULTS

On the first postoperative day, the intraocular pressure in the apraclonidine group (520 eyes: 15.5 +/- 4.9 mmHg) was significantly lower than that in the non-use group (577 eyes: 18.7 +/- 7.2 mmHg) (p < 0.001). The significant variables included preoperative intraocular pressure, apraclonidine use, sex (men > women), poor mydriasis, acetylcholine use, pseudoexfoliation, and diabetes mellitus.

CONCLUSIONS

Apraclonidine is useful in suppressing postoperative elevation of intraocular pressure.

Prolactin signalling in the mouse hypothalamus is primarily mediated by signal transducer and activator of transcription factor 5b but not 5a

Prolactin acts at multiple targets throughout the body, including the mammary gland, heart, liver, muscle and brain. Upon binding to its receptors, prolactin signals through the phosphorylation and thus activation of signal transducer and activator of transcription 5 (STAT5). There are two very similar STAT5 isoforms, termed STAT5a and STAT5b, which are selectively activated by prolactin in specific tissues. Various brain regions, including the hypothalamus, are prolactin responsive, although the STAT5 isoform involved in these actions is unknown. Immunohistochemical and western blot analysis were used to determine the expression and activation of STAT5a and STAT5b throughout the hypothalamus in adult wild-type and STAT5b-deficient mice. Both groups were pretreated with bromocriptine to suppress endogenous prolactin levels followed by the administration of ovine prolactin (10 mg/kg) for 45 min. STAT5a and STAT5b were expressed throughout the hypothalamus of wild-type mice. As expected, only STAT5a was detected in STAT5b-deficient mice, although, unexpectedly, there was a marked reduction in its expression compared to wild-type mice. When stimulated with prolactin, phosphorylated STAT5 was observed in the hypothalamus of wild-type but not STAT5b-deficient mice. By contrast, phosphorylated STAT5 was detected in mammary gland epithelial cells and adipocytes of STAT5b-deficient animals. Thus, although STAT5a was still expressed in the STAT5b-deficient mice, it was not phosphorylated in the hypothalamus in response to prolactin. These observations indicate that STAT5b but not STAT5a is the primary mediator of the action of prolactin in the hypothalamus. Despite the similarity between the two STAT5 isoforms, STAT5a was unable to compensate for the absence of STAT5b, suggesting that each isoform exhibits a unique biological activity.

Role of Ti 3d carriers in mediating the ferromagnetism of Co∶TiO2 anatase thin films

We study the surface and bulk electronic structure of the room-temperature ferromagnet Co∶TiO(2) anatase films using soft- and hard-x-ray photoemission spectroscopy with probe sensitivities of ∼1 and ∼10  nm, respectively. We obtain direct evidence of metallic Ti(3+) states in the bulk, which get suppressed to give a surface semiconductor, thus indicating the difference in electronic structure between surface and bulk. X-ray absorption and resonant photoemission spectroscopy reveal Ti(3+) electrons at the Fermi level (E(F)) and high-spin Co(2+) electrons occurring away from E(F). The results show the importance of the charge neutrality condition: Co(2+)+V(O)(2-)+2Ti(4+)↔Co(2+)+2Ti(3+) (V(O) is oxygen vacancy), which gives rise to the elusive Ti 3d carriers mediating ferromagnetism via the Co 3d-O 2p-Ti 3d exchange interaction pathway of the occupied orbitals.

Strong valence fluctuation in the quantum critical heavy fermion superconductor β-YbAlB4: a hard x-ray photoemission study

Electronic structures of the quantum critical superconductor β-YbAlB4 and its polymorph α-YbAlB4 are investigated by using bulk-sensitive hard x-ray photoemission spectroscopy. From the Yb 3d core level spectra, the values of the Yb valence are estimated to be ∼2.73 and ∼2.75 for α- and β-YbAlB4, respectively, thus providing clear evidence for valence fluctuations. The valence band spectra of these compounds also show Yb2+ peaks at the Fermi level. These observations establish an unambiguous case of a strong mixed valence at quantum criticality for the first time among heavy fermion systems, calling for a novel scheme for a quantum critical model beyond the conventional Doniach picture in β-YbAlB4.

Evidence for a correlated insulator to antiferromagnetic metal transition in CrN

We investigate the electronic structure of chromium nitride (CrN) across the first-order magnetostructural transition at T(N)∼286  K. Resonant photoemission spectroscopy (PES) shows a gap in the 3d partial density of states at the Fermi level and an on-site Coulomb energy U∼4.5  eV, indicating strong electron-electron correlations. Bulk-sensitive high-resolution (6 meV) laser PES reveals a clear Fermi edge indicating an antiferromagnetic metal below T(N). Hard x-ray Cr 2p core-level PES shows T-dependent changes across T(N) which originate from screening due to coherent states as substantiated by cluster model calculations using the experimentally observed U. Electrical resistivity confirms an insulator above T(N) (E(g)∼70  meV) becoming a disordered metal below T(N). Thus, CrN transforms from a correlated insulator to an antiferromagnetic metal, coupled to the magnetostructural transition.

Anomalous state sandwiched between Fermi liquid and charge ordered Mott-insulating phases of Ti4O7

The Magnéli phase Ti(4)O(7) exhibits two sharp jumps in resistivity with coupled structural transitions as a function of temperature at T(c1) approximately 142 K and T(c2) = 154 K. We have studied electronic structure changes across the two transitions using 7 eV laser, soft x-ray, and hard x-ray (HX) photoemission spectroscopy (PES). Ti 2p-3d resonant PES and HX PES show a clear metallic Fermi edge and mixed valency above T(c2). The low temperature phase below T(c1) shows a clear insulating gap of approximately 100 meV. The intermediate phase between T(c1) and T(c2) indicates a pseudogap coexisting with remnant coherent states. HX PES and complementary calculations have confirmed the coherent screening in the strongly correlated intermediate phase. The results suggest the existence of a highly anomalous state sandwiched between the mixed-valent Fermi liquid and charge ordered Mott-insulating phase in Ti(4)O(7).

Anomalous duality of 4f electrons in filled skutterudite CeOs4Sb12

We study the electronic structure of the filled skutterudite CeOs4Sb12 using photoemission spectroscopy (PES). Soft x-ray excited Ce 3d-4f resonant PES confirms the existence of Ce 4f states at the Fermi level (EF). Temperature dependent high-resolution laser-PES spectra reveal a pseudogap formation around EF, which can be explained in terms of the hybridization gap. Simultaneously, a sharp feature is formed just above EF with decreasing temperature. The heavy-fermion-like specific heat is attributed to the occupation of this feature. The results identify the origin of the anomalous coexistence of heavy-fermion and pseudogap behavior in terms of a symmetry dependent hybridization.

Recoil effect of photoelectrons in the Fermi edge of simple metals

High energy resolution photoelectron spectroscopy of conduction electrons in the vicinity of the Fermi edge in Al and Au at excitation energies of 880 and 7940 eV was carried out using synchrotron radiation. For the excitation energy of 7940 eV, the observed Fermi energy of Al shows a remarkable shift to higher binding energy as compared with that of Au, with accompanying broadening. This is due to the recoil effect of the emitted photoelectrons. The observed spectra are well reproduced by a simple model of Bloch electrons based on the isotropic Debye model.

Revisiting the valence-band and core-level photoemission spectra of NiO

We have reexamined the valence-band (VB) and core-level electronic structure of NiO by means of hard and soft x-ray photoemission spectroscopies. The spectral weight of the lowest energy state was found to be enhanced in the bulk sensitive Ni 2p core-level spectrum. A configuration-interaction model including a bound state screening has shown agreement with the core-level spectrum and off- and on-resonance VB spectra. These results identify the lowest energy states in the core-level and VB spectra as the Zhang-Rice (ZR) doublet bound states, consistent with the spin-fermion model and recent ab initio calculations within dynamical mean-field theory. The results indicate that the ZR character first ionization (the lowest hole-addition) states are responsible for transport properties in NiO and doped NiO.

Temperature-dependent localized excitations of doped carriers in superconducting diamond

Laser-excited photoemission spectroscopy is used to show that the doped carriers in metallic or superconducting diamond couple strongly to the lattice via high-energy (approximately 150 meV) optical phonons, with direct observations of localized Franck-Condon multiphonon sidebands appearing as Fermi-edge replicas. It exhibits a temperature-dependent spectral weight transfer from higher to lower energy sidebands and zero-phonon Fermi-edge states. The quantified coupling strength shows a systematic increase on lowering temperature, implicating its relation to the normal state transport and superconductivity.

Observation of a superconducting gap in boron-doped diamond by laser-excited photoemission spectroscopy

We investigate the temperature (T)-dependent low-energy electronic structure of a boron-doped diamond thin film using ultrahigh resolution laser-excited photoemission spectroscopy. We observe a clear shift of the leading edge below T=11 K, indicative of a superconducting gap opening (Delta approximately 0.78 meV at T=4.5 K). The gap feature is significantly broad and a well-defined quasiparticle peak is lacking even at the lowest temperature of measurement (=4.5 K). We discuss our results in terms of disorder effects on the normal state transport and superconductivity in this system.

Bulk- and surface-sensitive high-resolution photoemission study of two mott-hubbard systems: SrVO3 and CaVO3

We study the electronic structure of Mott-Hubbard systems SrVO3 and CaVO3 with bulk and surface-sensitive high-resolution photoemission spectroscopy, using a vacuum ultraviolet laser, synchrotron radiation, and a discharge lamp (hv = 7-21 eV). A systematic suppression of the density of states (DOS) within approximately 0.2 eV of the Fermi level (EF) is found on decreasing photon energy, i.e., on increasing bulk sensitivity. The coherent band in SrVO3 and CaVO3 is shown to consist of surface and bulk-derived features, separated in energy. The stronger distortion on surface of CaVO3 compared to SrVO3 leads to a higher surface metallicity in the coherent DOS at EF, consistent with recent theory.

Multimodality treatments with endoscopic mucosal resection of esophageal squamous cell carcinoma with submucosal invasion

BACKGROUND AND STUDY AIMS

A standard treatment for esophageal squamous cell carcinoma (SCC) with submucosal invasion is considered to be radical resection at present. In this study, we evaluated the efficacy of multimodality treatments with endoscopic mucosal resection (EMR) of esophageal SCC with submucosal invasion.

METHOD

Eighteen cases of SCC with submucosal invasion were treated with EMR. Lymphatic invasion was found in 11 cases (67%), and there were no cases of blood vessel invasion. EMR was performed prior to any other treatment. Chemotherapy and/or radiotherapy were added if indicated by the histopathological features.

RESULTS

There were no cases of local recurrence. Lymph-node recurrence was detected in 1 case treated with EMR alone. There were no cases of cancer death. The overall survival rate was 83% in all patients.

CONCLUSIONS

Multimodality treatments with EMR were effective in treating esophageal SCC with submucosal invasion.

Linkage and mapping analysis of a non-susceptibility gene to densovirus (nsd-2) in the silkworm, Bombyx mori

Nonsusceptibility to Bombyx mori densovirus type 2 (BmDNV-2) is controlled by a recessive non-susceptibility gene, nsd-2 (non-susceptibility to DNV-2) in B. mori. Taking advantage of a lack of crossing over in females, reciprocal backcrossed F1 (BF1) progeny were used for linkage analysis and mapping of nsd-2 using silkworm strains C124 and 902, which are classified as being highly susceptible and non-susceptible to DNV-2, respectively. BF1 larvae were inoculated twice with DNV-2 virus at the first and second instar stages. DNA was extracted from each of the surviving fifth instar larvae and analysed by RFLP inheritance patterns using probes specific to each of the 28 linkage groups of B. mori. Our results indicated that the non-susceptibility gene was linked to linkage group 17, since all surviving larvae showed the homozygous profile of strain 902 in their genotype. The other linkage groups showed mixtures of heterozygous and homozygous genotypes, indicating an independent assortment. A linkage map of 30.6 cM was constructed for linkage group 17 with nsd-2 mapped at 24.5 cM and three closely linked cDNA markers were identified.

Adenocarcinoma of the esophagogastric junction: a summary of responses to a questionnaire on adenocarcinoma of the esophagus and the esophagogastric junction in Japan

Adenocarcinoma of the esophagogastric junction is recognized as a distinct clinical entity; however, the choice of surgical approaches is controversial. To analyze the results of surgery among patients with adenocarcinoma of the esophagus (type I) and the cardia (type II) based on Siewert's classification in Japan, surgical procedures, histopathologic characteristics, and outcome were re-evaluated according to the TNM classification in 1263 patients with adenocarcinoma of the esophagus (type I) and the cardia (type II) through a questionnaire sent to the members of the Japanese Society of Esophageal Diseases. One hundred and thirty-four (10.6%) patients had type I tumors and 1129 (89.4%) patients had type II tumors. There were significant differences in sex distribution and associated intestinal metaplasia in the esophagus between patients with type I and type II tumors. Although different surgical approaches were performed, the overall 5-year survival rate was 53% without any difference between the two groups. The significant prognostic factors in general linear models were R category, pN category, and differentiation, but not pT category. There was no difference in survival between patients with stage IIB and III disease. The survival rate of the patients who underwent a transhiatal approach was similar to that of those undergoing a transthoracic approach. The results suggest that Siewert's classification (type I and type II) is useful in planning treatment strategy for adenocarcinoma of the esophagogastric junction. Lymph node metastasis was the most important prognostic factor, and staging based on the number of lymph node metastases or the extent of lymph node metastasis is necessary.

Observation of fluorapatite formation under hydrolysis of tetracalcium phosphate in the presence of KF by means of soft X-ray emission and absorption spectroscopy

The effect of fluoride on the hydrolysis of tetracalcium phosphate (TTCP; Ca4(PO4)2O) in 0.1 mol/l KH2PO4 containing 62-83 mmol/l KF was studied with the help of X-ray fluorescence measurements. Fluorine X-ray emission and absorption spectra of the final product of hydrolysis and reference samples (CaF2 and Ca5(PO4)3F) were measured at Beamline BL-2C of Photon Factory (PF, Tsukuba). Based on these measurements we concluded that hydrolysis of TTCP in the presence of KF converts it into fluorapatite. Formation of CaF2, which is often found in the hydrolysis of hydroxyapatite at high fluoride concentration, was not observed.

[Reconstruction after cervical esophagectomy using a free jejunal graft]

Reconstruction after cervical esophagectomy using a free jejunal graft and forming an additional "vocal canal" are described. It is necessary to pay attention to several points, for example, selection of the jejunal graft, selection of the cervical vessels for anastomosis, technique of hypopharyngeal-jejunal anastomosis, and postoperative management of the anastomotic vessels. These contribute to the improvement of patient quality of life. Forming an additional "vocal canal" in patients who underwent radical surgery is particularly desirable. In this article, we introduce our operative method.

Immunocytochemical detection of circulating esophageal carcinoma cells by immunomagnetic separation

BACKGROUND

Recent developments in detection of micrometastasis have revealed a considerable incidence of systemic disease in patients who would previously have been diagnosed as having solid tumours only. The purpose of this study was to investigate the prevalence and clinical significance of circulating carcinoma cells in patients with esophageal squamous cell carcinoma (ESCC).

MATERIALS AND METHODS

Peripheral blood samples from 47 primary ESCC patients were enriched by immunomagnetic separation (IMS) using Ber-EP4-conjugated beads (Dynabeads anti-epithelial cell) and immunostained with an anti-cytokeratin (anti-CK) antibody. We assayed samples from 12 patients to compare the detection of CK-reactive cells using IMS with the detection of CK 19 mRNA using a reverse transcriptase-polymerase chain reaction (RT-PCR) method.

RESULTS

CK-reactive cells were observed in 18 out of 47 patients (38%). The detection rate was closely correlated with the stage of disease (TNM stage) (p = 0.0017). In 33 patients who underwent esophagectomy, 4 out of 7 patients (57%) positive for CK cells and only 2 out of 26 patients (7.7%) negative suffered from recurrence in the distant lymph nodes or lungs (p = 0.0108). When IMS and RT-PCR were compared, all 3 samples that were CK-positive by IMS had CK 19 mRNA detected by RT-PCR. However, the other 4 samples with CK 19 mRNA by RT-PCR were negative for CK cells by IMS. Of 7 patients positive for CK-reactive cells before chemotherapy or chemoradiotherapy, 4 patients negative after treatment survived but 3 patients who remained positive died within 6 months.

CONCLUSION

Immunocytochemical detection of circulating carcinoma cells by IMS may be a specific method for the diagnosis of systemic disease and for monitoring treatment response.

[Modified Jekler and Lhotka operation in minimized laparotomy for achalasia]

The rationale for surgery in achalasia is to reduce lower esophageal sphincter (LES) pressure and recontruct an antireflux mechanism. Fundopexy as an antireflux procedure after LES myotomy (modified Heller myotomy), called the Jekler and Lhotka method or the Heller and Dor operation, is commonly performed as standard surgery. In our institution, this method has been used since 1982. We have performed the modified Jekler and Lhotha method including long myotomy to confirm complete reduction of LES pressure as measured by intraoperative manometry and fundopexy plus posterior wall fixation to contract the long abdominal esophagus since 1986. Satisfactory results with this procedure have been obtained and reported. Furthermore, we have recently performed this procedure with minilaparotomy. In this review, we describe the modified Jekler and Lhotha method in minimized laparotomy and evaluate this procedure using intraoperative manometry.

Analysis of postoperative complications after esophagectomy for esophageal cancer in patients receiving neoadjuvant therapy

Postoperative complications were investigated in 72 patients who received neoadjuvant therapy with esophagectomy. Preoperative chemotherapy consisted of 5-fluorouracil (700 mg/m2/day, on days 1 to 5), cisplatinum (70 mg/m2/day, on day 1) and leucovorin (20 mg/m2/day, on days 1 to 5). Preoperative chemoradiotherapy consisted of cisplatinum combined chemotherapy and radiotherapy (total dosage of 30-70 Gy). The incidence of postoperative pneumonia (16%) and anastomotic leakage (24%) in the preoperative chemotherapy group was slightly higher than that in the control group (n = 506), and mortality (6.0%) after esophagectomy in the preoperative chemotherapy group was higher than that (2.4%) of the control group. Postoperative morbidity and mortality were observed more frequently in patients who received two cycles of the chemotherapy than those receiving only one cycle. Postoperative complications occurred more frequently in patients suffering high grade toxicities due to the preoperative chemotherapy. The highest preoperative serum creatinine value correlated to that of postoperative period (r = 0.6494). The use of the preoperative chemoradiotherapy with a total exposure dosage of 60 Gy or more significantly increased the postoperative pneumonia rate (67%; p < 0.05) compared to the group receiving 40 Gy or less. The mortality rate (33%) also increased. The second cycle of the preoperative chemotherapy should be cancelled if patients suffer high grade toxicities during or after the first cycle, and the total exposure dosage of the preoperative chemoradiotherapy should be limited to 40 Gy or less.

Cholecystokinin stimulates ascorbic acid secretion through its specific receptor in the perfused stomach of rats

We have previously demonstrated that endogenous ascorbic acid is secreted into the gastric lumen by cholinergic stimulation in both conscious pylorus-ligated rats and the perfused stomach of unconscious rats, and that gastrin, a potent gastric stimulatory peptide hormone, has no effect. In the present study, the effects of some gastrointestinal peptide hormones on gastric ascorbic acid secretion were further examined in the perfused stomach of rats. An intravenous administration of cholecystokinin octapeptide (CCK-8) significantly increased gastric ascorbic acid secretion at a dose of 1.0 and 4.0 micrograms/kg, whereas the other three peptides examined, bombesin, neurotensin and substance P, showed no or little effect at the doses which were quite commonly employed for evaluation of various gastric functions. CCK-8-induced ascorbic acid secretion was reduced by pretreatment with proglumide, which is a CCK receptor antagonist, but not by pretreatment with atropine. These results indicate that gastric ascorbic acid secretion is physiologically regulated not only by muscarinic receptor-associated cholinergic stimulation but also by CCK receptor-associated humoral stimulation.

CYFRA 21-1 as a tumor marker for squamous cell carcinoma of the esophagus

This study assessed the clinical value of CYFRA 21-1 in comparison with squamous cell carcinoma antigen (SCC-Ag), carcinoembryonic antigen (CEA), and carbohydrate antigen 19-9 (CA19-9) in patients with esophageal squamous cell carcinoma. In 112 primary cancer patients, the diagnostic sensitivity of CYFRA 21-1 (33.9%) was superior to SCC-Ag (28.6%), CEA (12.5%), and CA19-9 (6.3%). Levels of CYFRA 21-1 were closely correlated with TNM stage and wee below the cutoff value in all 21 patients with stage I disease. All 38 patients with a CYFRA 21-1 level over the cutoff value among the 80 patients who underwent esophagectomy had lymph node metastases (pN1). A correlation was found between CYFRA 21-1 levels and clinical response in serial measurements of 21 patients who received chemotherapy or chemo radiotherapy. Our findings suggest that CYFRA 21-1 is not useful for diagnosis, but that it is valuable for monitoring the efficacy of therapy.

Neoadjuvant chemotherapy with cisplatinum/5-fluorouracil/low-dose leucovorin for advanced squamous cell carcinoma of the esophagus

Forty-four patients with advanced esophageal squamous cell carcinoma were treated with biochemical modulated combination chemotherapy and surgery. Treatment consisted of cisplatinum (70 mg/m2/day 1, day 22), 5-fluorouracil (5-FU; 700 mg/m2/day, days 1-5, 22-26), and leucovorin (20 mg/m2/day, days 1-5, 22-26) with nutritional support, and surgery (days 42-70, mean day 56). Surgery consisted of subtotal esophagectomy with extended lymphadenectomy. Postoperative adjuvant chemotherapy or additional irradiation to the mediastinum was restricted to patient with residual tumors. Clinical response rate was 63.6% in primary tumor, 52.6% in intramural metastasis, 100% in intraepithelial spread, and 30.9% for metastatic lymph nodes. There was a slight disagreement between the result of evaluation of histological and clinical effect. The incidence of postoperative complications was 25%, and the mortality rate was 2.3%. Overall 1-, 2-, 3-, and 4-year survival rates of the patients were 57%, 37.9%, 28.5%, and 28.5%, respectively. The median survival time was 14.7 months. Responders survived longer than nonresponders. The histological responders survived longer than clinical responders. The 4-year survival rate of patients without residual tumor after treatment was 75% in the superficial cases, 51% in the locoregional cases, and 50% in the widespread cases.

[Effective combined injection method of fluoropyrimidine and platinum--application for advanced esophageal cancer]

In patients with esophageal cancer, combined chemotherapy is usually given as a part of multimodality treatment and therefore undesirable toxicity should be diminished. Recently, the most standard protocol against esophageal cancer has been Cisplatin/5-FU combination, of which the response rate is 40-60%. We showed the development of chemotherapy and chemoradiotherapy using Cisplatin/5-FU for esophageal cancer. In recent Japanese protocols, continuous infusion of Cisplatin for several days or bolus injection of low-dose Cisplatin are supposed to be mainstream. The supra additive effect of leucovorin to Cisplatin +5-FU considering biochemical modulation is confirmed, and Cisplatin/5-FU/adriamycin protocol study is ongoing.

[The postoperative care and treatment in esophageal cancer (4). Postoperative follow up-(recurrence, nutritional management and after-care of IC)]

The points of the postoperative care in radical operation of esophageal cancer are followings. 1) Postoperative nutritional management: In the reconstruction using gastric tube, we make Witzel's gastrostomy in antrum of regardless of the reconstructive routes and transfer to enteral tube-feeding to assist the oral food-taking amount. These management is not only attributing to assist early return to working but also effective to prevent the loss of postoperative physical strength in older patients. 2) Postoperative adjuvant therapy: The esophageal cancer is the diseases that react chemo- and radio-therapy, so most of advanced cases were treated with adjuvant therapy. Nowadays, it is essential for patients to explain the real diagnosis, treatment regimen, then to agree to the informed concent. After informed, the tender mental consult during treatment and outpatient service is required for mental burden. 3) Postoperative follow-up: The recognition of postoperative QOL, early detection of recurrence are mostly emphasized during 2 years after operation. The occurrence of secondary cancer (gastric cancer, cervico-pharyngeal cancer, colorectal cancer etc.) are seen in even 5-10 years after operation. Then the long-term periodical examination and life care are needed.

[The efficacy of pyloroplasty affecting to oral-intake quality of life using reconstruction with gastric tube post esophagectomy]

After resection of esophageal carcinoma, pyloroplasty was undergone due to vagal denervation. Especially the ability of oral-taking is related to the return of general societies after operation. This was a randomized study on whether pyloroplasty was effective by functional and nutritional evaluations. From 1992 to 1995, 67 patients with esophageal carcinoma underwent subtotal esophagectomy and reconstruction using a gastric tube. Thirty-four patients were randomized into the pyloroplasty group (P), and 33 into the control group (N). The functional evaluation was done with (1) food-taking scoring (2) A foods with barium granules ejection time (3) a gastric emptying time of 99m Technecium (4) 75 g OGTT. The nutritional evaluation were (1) Rapid Turn-over Protein (RTP) (2) Total Lymphocyte Count (TLC) (3) ONODERA's Prognostic Nutritional Count (PNI) (4) Fluctuation rate of body weight. The elevations were performed 1 and 6 months after operation. Functional evaluation were as follows. (1) Quantity of oral-intake was not significant different between (P) and (N) both improving those quantities in 6 months. Regarding several complaints including in regurgitation, (P) had a few symptoms comparing to (N), almost half of cases complained of some symptoms and did not improving in 6 months. (2) The food ejection time of foods were 19.6 +/- 31.0 min, in (P), 32.9 +/- 37.2 min, in (N), (3) In the Tc gastric emptying time, we calculated as 50% ejecting time and residual rate of 30 min. In 50% ejecting time less than 20 min., (P) shared in 65, 80%, (N) in 39, 40% in 1 and 6 months. (4) In 75 g OGTT there were no significant difference between both groups, though several cases showed the dumping syndrome. In the nutritional evaluation, in RTP, TLC, PNI, and postope, body weight, there were no differences between the two groups. In conclusion, pyloroplasty several symptoms related to oral intake including regurgitation feelings, and in functional evaluation, there shows faster gastric emptying though there were no significant differences in the nutritional phases at 6 months follow-up. The results suggest that this procedure is not essential but it affects to the oral-intake QOL effectively.

Expression of p53 protein related to human papillomavirus and DNA ploidy in superficial esophageal carcinoma

We examined the p53 protein and human papilloma virus (HPV) by immunohistochemistry and DNA ploidy by cytofluorometry in paraffin-embedded esophageal carcinoma tissue specimens. Sixty-one patients with superficial esophageal carcinoma were operated on between 1983 and 1991 without any prior treatment. Immunostaining of the anti-p53 protein antibody (CM1) was positive in 32 carcinomas (52%). Patients with p53-positive tumors had a poorer outcome than those with p53-negative tumors (P < 0.05). In addition, patients with p53-positive tumors did not have any characteristic site of relapse. Only 5 of the 61 patients (8.2%) had HPV-positive tumors. One of these 5 carcinomas expressed both p53 protein and HPV. Three patients with HPV-positive tumors which had invaded the submucosal layer died of relapse. A determination of DNA ploidy revealed 30 patients with aneuploid tumors, 13 with polyploid tumors and 18 with diploid tumors. The outcome of the patients with aneuploid tumors was worse than that of the patients with diploid tumor (P < 0.05). p53 protein expression was not associated with DNA ploidy; however, the 16 patients who had both p53-positive and aneuploid tumors had a worse prognosis than patients with p53-negative and aneuploid tumors (P < 0.01). These findings suggest that p53 protein expression in conjunction with DNA ploidy may be a useful indicator in evaluating the prognosis of patients with superficial esophageal carcinoma.

[Clinico-pathological study of preoperative chemotherapy of esophageal cancer by combined use of three drugs--cisplatin, 5-FU and leucovorin]

We compared the clinical and pathological effects of preoperative combination chemotherapy using CDDP, 5-FU, and response rate for the primary lesion, an 81.8% response rate for intramural metastasis, 100.0% for intraepitherial spread, and a low response rate of 40.7% for lymph node metastasis. Pathological examination showed a 55.2% response rate for the primary lesion. There were seven cases in which the clinical assessment indicated that treatment was effective and pathological examination showed that it was ineffective, and three cases in which pathological examination showed a better response than clinical assessment. Cases showing a better clinical response included in which necrotic cancer lesion had disappeared due to absorption by the time of pathological examination, those with tumor regrowth after preoperative evaluation, those evaluated as showing a poor response due to residual cancer at the margin. Cases showing a better pathological response included those having remaining necrotic tissues and those having myoma beneath tumor. For intramural metastatic lesions, the pathological response rate was 42.9%, being lower than the clinical response rate. Metastasis to 209 lymph nodes showed a 23.0% response rate, with the abdominal nodes showing a poor response in comparison with those of the cervix and mediastinum. In 26 patients receiving preoperative radiotherapy, there was a significantly higher frequency of such changes as fibrous scar tissue, foreign body giant cells, vacuolation of tumor cells, and hyaloid degeneration of the lesion in comparison with the group receiving chemotherapy. Another difference was that the radiotherapy group showed a higher response of tumors with venous and lymphatic involvement.(ABSTRACT TRUNCATED AT 250 WORDS)