Antidepressant properties of voluntary exercise mediated by gut microbiota.

Although regular exercise has been reported to prevent depression, it has not been clarified whether the gut microbiota is involved in the factors that prevent depression through exercise. We investigated the effects of voluntary exercise on the gut microbiota and the prevention of depression-like behaviors using mice. C57BL/6 J male mice were subjected to 10 weeks of sedentary control or wheel running, then they were subjected to social defeat stress (SDS). Exercise attenuated that sucrose drinking was decreased by SDS treatment. Exercise increased the expression of Bdnf and decreased expression of Zo-1 and Claudin5 in the brain. Fecal Turicibacter, Allobaculum, and Clostridium sensu stricto, and propionate in the cecum were decreased by the exercise. Voluntary exercise-induced antidepressant properties might be partially caused by suppression of serotonin uptake into gut microbiota and increase the permeability of the blood-brain barrier via reduced propionate production.

Acetyl-L-carnitine attenuates Poly I:C-induced sickness behavior in mice.

Fatigue is accompanied by a decrease in physical activity or malaise, and might be reduced by acetyl-L-carnitine (ALC) administration. The purpose of this study was to investigate the preventive effects of ALC on Poly I:C-induced sickness behavior in mice. For the experiment, male C3H/HeN mice were used and treated with ALC for 5 days before Poly I:C administration. ALC administration attenuated the decrease in wheel behavior activity of mice at 24 h after Poly I:C administration and ALC-treated mice quickly recovered from the sickness behavior. The gene expression of brain-derived neurotrophic factor (BDNF) in the cerebrum and hippocampus, which is associated with physical activity, was higher in the ALC-treated group. Translocator protein 18kDa (TSPO), which has cytoprotective effects, was up-regulated in the cerebrum and hippocampus, suggesting that ALC suppressed the decrease in activity induced by Poly I:C treatment through enhancement of cytoprotective effects in the brain.

FSBC: fast string-based clustering for HT-SELEX data.

BACKGROUND: The combination of systematic evolution of ligands by exponential enrichment (SELEX) and deep sequencing is termed high-throughput (HT)-SELEX, which enables searching aptamer candidates from a massive amount of oligonucleotide sequences. A clustering method is an important procedure to identify sequence groups including aptamer candidates for evaluation with experimental analysis. In general, aptamer includes a specific target binding region, which is necessary for binding to the target molecules. The length of the target binding region varies depending on the target molecules and/or binding styles. Currently available clustering methods for HT-SELEX only estimate clusters based on the similarity of full-length sequences or limited length of motifs as target binding regions. Hence, a clustering method considering the target binding region with different lengths is required. Moreover, to handle such huge data and to save sequencing cost, a clustering method with fast calculation from a single round of HT-SELEX data, not multiple rounds, is also preferred. RESULTS: We developed fast string-based clustering (FSBC) for HT-SELEX data. FSBC was designed to estimate clusters by searching various lengths of over-represented strings as target binding regions. FSBC was also designed for fast calculation with search space reduction from a single round, typically the final round, of HT-SELEX data considering imbalanced nucleobases of the aptamer selection process. The calculation time and clustering accuracy of FSBC were compared with those of four conventional clustering methods, FASTAptamer, AptaCluster, APTANI, and AptaTRACE, using HT-SELEX data (>15 million oligonucleotide sequences). FSBC, AptaCluster, and AptaTRACE could complete the clustering for all sequence data, and FSBC and AptaTRACE performed higher clustering accuracy. FSBC showed the highest clustering accuracy and had the second fastest calculation speed among all methods compared. CONCLUSION: FSBC is applicable to a large HT-SELEX dataset, which can facilitate the accurate identification of groups including aptamer candidates. AVAILABILITY OF DATA AND MATERIALS: FSBC is available at http://www.aoki.ecei.tohoku.ac.jp/fsbc/.

Responsiveness of the Self-Administered Foot Evaluation Questionnaire (SAFE-Q) in patients with hallux valgus.

BACKGROUND: In this study, we investigated the responsiveness of the Self-Administered Foot Evaluation Questionnaire (SAFE-Q) for patient's assessment before and after hallux valgus surgery. METHODS: Patient-reported answers on the SAFE-Q and Short Form-36 (SF-36) before and at a mean of 3-4 and 9-12 months after hallux valgus surgery were analyzed. Data of 100 patients (92 women, eight men) from 36 institutions throughout Japan were used for analysis. RESULTS: In all subscales of the SAFE-Q, the trend of increased scores after surgery was statistically significant (P < 0.001). Among the patients with available scores both before and at 9-12 months after surgery (n = 66), the largest effect sizes (ESs) were observed for shoe-related (1.60), pain and pain-related (1.05), and general health and well-being (0.84) scales. In the SF-36 (n = 64), the largest ES was observed for the bodily pain scale (0.86). Less notable changes were observed for the remaining SF-36 domains. CONCLUSION: The SAFE-Q is the first patient-reported outcome measure which includes a quality of life assessment of shoes. In our cohort, the most remarkable responsiveness was observed for the shoe-related subscale. Based on its responsiveness, the SAFE-Q appears to be sufficient for evaluation of foot-related quality of life before and after surgery.

Aichi cohort study of the prognosis in patients newly initiated into dialysis (AICOPP): baseline characteristics and trends observed in diabetic nephropathy.

BACKGROUND: Over 300,000 patients receive maintenance dialysis in Japan; managing these patients is extremely important. This study aimed to report on prior management of chronic kidney diseases and prognostication after dialysis initiation. PATIENTS AND METHODS: Seventeen institutions participated in the Aichi cohort study of prognosis in patients newly initiated into dialysis and recruited patients over a period of 2 years. Exclusion criteria were (1) patients under 20 years; (2) patients who died before hospital discharge; and (3) patients who could not provide consent. RESULT: Here, we showed data on dialysis initiation time. Of 1524 patients with mean age of 67.5 ± 13.0 years, 659 patients were put on dialysis following diabetic nephropathy diagnosis. At dialysis initiation time, creatinine and estimated glomerular filtration rate levels were 8.97 ± 3.21 mg/dl and 5.45 ± 2.22 ml/min/1.73 m2, respectively. Medications taken were angiotensin II receptor blockers in 866; angiotensin-converting enzyme inhibitors in 135; calcium antagonist in 1202; and diuretics, alone or in combination, in 1059. Among patients with diabetic nephropathy, many had increased body weight and systolic blood pressure and were taking loop and thiazide diuretics at dialysis initiation time. Many patients with diabetic nephropathy had coronary artery disease and percutaneous coronary intervention. CONCLUSION: Many patients with diabetic nephropathy who registered for this study had coronary artery disease and problems with excess body fluid. Further analyses may clarify how underlying conditions and disease management before and after dialysis initiation affect prognosis.

Neural Radiance Field-Inspired Depth Map Refinement for Accurate Multi-View Stereo.

In this paper, we propose a method to refine the depth maps obtained by Multi-View Stereo (MVS) through iterative optimization of the Neural Radiance Field (NeRF). MVS accurately estimates the depths on object surfaces, and NeRF accurately estimates the depths at object boundaries. The key ideas of the proposed method are to combine MVS and NeRF to utilize the advantages of both in depth map estimation and to use NeRF for depth map refinement. We also introduce a Huber loss into the NeRF optimization to improve the accuracy of the depth map refinement, where the Huber loss reduces the estimation error in the radiance fields by placing constraints on errors larger than a threshold. Through a set of experiments using the Redwood-3dscan dataset and the DTU dataset, which are public datasets consisting of multi-view images, we demonstrate the effectiveness of the proposed method compared to conventional methods: COLMAP, NeRF, and DS-NeRF.

Slanted and Standard Lateral Rectus Recession Procedures for Convergence Insufficiency-Type Intermittent Exotropia in Children: A Retrospective Cohort Study.

Purpose: To evaluate the efficacy and safety of slanted bilateral lateral rectus recession (BLR-rec) for treating convergence insufficiency-type intermittent exotropia (CI-IXT) in children. Methods: In this retrospective cohort study, 26 patients aged <16 years with CI-IXT who underwent BLR-rec between August 2016 and July 2021 with six months of follow-up data post-surgery were classified into slanted BLR-rec group (n = 14) and standard BLR-rec group (n = 12; equal-length recession of the upper and lower horns of the LR muscle). Surgical outcomes were compared between the groups. Results: In the slanted and standard groups, the preoperative distance exodeviation was 27.9 ± 5.5 and 30.8 ± 10.0 prism diopter (PD) (p = 0.63), near exodeviation was 41.1 ± 5.6 and 42.9 ± 9.2 PD (p = 0.75), and difference between near and distance deviation (N-D deviation difference) was 13.2 ± 3.2 and 12.1 ± 3.3 PD (p = 0.30), respectively. The ratio of postoperative and preoperative N-D deviation difference was compared between the slanted BLR and standard BLR groups at six months postoperatively. The results revealed that the ratio for slanted-BLR was 0.44 ± 0.19, and for standard-BLR was 0.84 ± 0.24. In the standard group, stereoacuity remained unchanged post-surgery compared to that pre-surgery, while the slanted group showed significant improvement (p < 0.05, Wilcoxon signed-rank test). Conclusion: Compared with the standard BLR-rec procedure, the slanted BLR-rec procedure reduced N-D deviation differences in CI-IXT, positively impacting gross stereopsis.

Image quality improvement in single plane-wave imaging using deep learning.

In ultrasound image diagnosis, single plane-wave imaging (SPWI), which can acquire ultrasound images at more than 1000 fps, has been used to observe detailed tissue and evaluate blood flow. SPWI achieves high temporal resolution by sacrificing the spatial resolution and contrast of ultrasound images. To improve spatial resolution and contrast in SPWI, coherent plane-wave compounding (CPWC) is used to obtain high-quality ultrasound images, i.e., compound images, by coherent addition of radio frequency (RF) signals acquired by transmitting plane waves in different directions. Although CPWC produces high-quality ultrasound images, their temporal resolution is lower than that of SPWI. To address this problem, some methods have been proposed to reconstruct a ultrasound image comparable to a compound image from RF signals obtained by transmitting a small number of plane waves in different directions. These methods do not fully consider the properties of RF signals, resulting in lower image quality compared to a compound image. In this paper, we propose methods to reconstruct high-quality ultrasound images in SPWI by considering the characteristics of RF signal of a single plane wave to obtain ultrasound images with image quality comparable to CPWC. The proposed methods employ encoder-decoder models of 1D U-Net, 2D U-Net, and their combination to generate the high-quality ultrasound images by minimizing the loss that considers the point spread effect of plane waves and frequency spectrum of RF signals in training. We also create a public large-scale SPWI/CPWC dataset for developing and evaluating deep-learning methods. Through a set of experiments using the public dataset and our dataset, we demonstrate that the proposed methods can reconstruct higher-quality ultrasound images from RF signals in SPWI than conventional method.

Validity and reliability of a self-administered foot evaluation questionnaire (SAFE-Q).

BACKGROUND: The Japanese Society for Surgery of the Foot (JSSF) is developing a QOL questionnaire instrument for use in pathological conditions related to the foot and ankle. The main body of the outcome instrument (the Self-Administered Foot Evaluation Questionnaire, SAFE-Q version 2) consists of 34 questionnaire items, which provide five subscale scores (1: Pain and Pain-Related; 2: Physical Functioning and Daily Living; 3: Social Functioning; 4: Shoe-Related; and 5: General Health and Well-Being). In addition, the instrument has nine optional questionnaire items that provide a Sports Activity subscale score. The purpose of this study was to evaluate the test-retest reliability of the SAFE-Q. PATIENTS AND METHODS: Version 2 of the SAFE-Q was administered to 876 patients and 491 non-patients, and the test-retest reliability was evaluated for 131 patients. In addition, the SF-36 questionnaire and the JSSF Scale scoring form were administered to all of the participants. Subscale scores were scaled such that the final sum of scores ranged between zero (least healthy) to 100 (healthiest). RESULTS: The intraclass correlation coefficients were larger than 0.7 for all of the scores. The means of the five subscale scores were between 60 and 75. The five subscales easily separated patients from non-patients. The coefficients for the correlations of the subscale scores with the scores on the JSSF Scale and the SF-36 subscales were all highly statistically significantly greater than zero (p < 0.001). The means for the five JSSF Scale classification groups fell within a relatively narrow range, indicating that the SAFE-Q labels are sufficiently similar to permit their use for all of the JSSF Scale classifications. CONCLUSION: The present study revealed that the test-retest reliability is high for each subscale. Consequently, the SAFE-Q is valid and reliable. In the future, it will be beneficial to test the responsiveness of the SAFE-Q.

Pose Estimation of Ultrasound Probe Using CNN and RNN with Image Reconstruction Loss.

It is necessary to estimate the pose of the probe with high accuracy to reconstruct 3D ultrasound (US) images only from US image sequences scanned by a 1D-array probe. We propose the probe pose estimation method using Convolutional Neural Network (CNN) with training by image reconstruction loss. To calculate the image reconstruction loss, we use the image reconstruction network which consists of an encoder that extracts features from the two US images and a decoder that reconstructs the intermediate US image between the two images. CNN is trained to minimize the image reconstruction loss between the ground-truth image and the reconstructed image. Through experiments, we demonstrate that the proposed method exhibits efficient performance compared with the conventional methods.

Face Attribute Estimation Using Multi-Task Convolutional Neural Network.

Face attribute estimation can be used for improving the accuracy of face recognition, customer analysis in marketing, image retrieval, video surveillance, and criminal investigation. The major methods for face attribute estimation are based on Convolutional Neural Networks (CNNs) that solve face attribute estimation as a multiple two-class classification problem. Although one feature extractor should be used for each attribute to explore the accuracy of attribute estimation, in most cases, one feature extractor is shared to estimate all face attributes for the parameter efficiency. This paper proposes a face attribute estimation method using Merged Multi-CNN (MM-CNN) to automatically optimize CNN structures for solving multiple binary classification problems to improve parameter efficiency and accuracy in face attribute estimation. We also propose a parameter reduction method called Convolutionalization for Parameter Reduction (CPR), which removes all fully connected layers from MM-CNNs. Through a set of experiments using the CelebA and LFW-a datasets, we demonstrate that MM-CNN with CPR exhibits higher efficiency of face attribute estimation in terms of estimation accuracy and the number of weight parameters than conventional methods.

LPS-induced TNF-α production is attenuated by intake with PHGG via gut microbial fermentation in mice.

OBJECTIVES: Intake of dietary fibers promotes the production of short-chain fatty acids (SCFAs), which can affect host inflammation via gut microbial fermentation. Although partially hydrolyzed guar-gum (PHGG) is a water-soluble dietary fiber with lower viscosity, its benefits in acute inflammation are yet to be determined. The aim of this study was to investigate the effect of PHGG intake on the lipopolysaccharide (LPS)-induced tumor necrosis factor (TNF)-α production. METHODS: Nine-wk-old male C3 H/HeN mice were used in this study, and they were randomly divided into control diet (CD) and CD + 5% PHGG (GGCD) groups. After a dietary intervention of 6 wk, LPS (1 mg/kg) was injected into the orbital vein. Plasma TNF-α concentration and SCFAs in cecum contents were then measured. Also, the effect of gut microbiota on LPS-induced TNF-α production was evaluated in PHGG-fed mice before and after antibiotic treatment. RESULTS: PHGG intake accelerated a dramatic suppression of LPS-induced TNF-α production (P < 0.01). PHGG-induced low pH in feces (P < 0.05) indicates that the gut microbiota induced high fermentation. Indeed, SCFAs in cecum contents of GGCD mice were significantly higher than in the CD group (P < 0.05). Furthermore, PHGG intake after antibiotic treatment did not induce the suppression of TNF-α. CONCLUSION: These results demonstrated that inflammation was inhibited by habitual PHGG ingestion, suggesting that this phenomenon might be associated with changes in gut microbiota-induced SCFAs production.

Perfusion defects in non-enlarged metastatic lymph nodes using vessel wall magnetic resonance imaging: Detection performance and diagnostic value.

A perfusion defect (PD) in non-enlarged lymph nodes (LNs) of oral squamous cell carcinoma (OSCC) is the most reliable radiological criterion for the diagnosis of metastasis. However, conventional contrast-enhanced (CE) T1 weighted images using turbo spin echo (TSE) sequence is limited in detecting PD in non-enlarged LNs due to flow artifacts from cervical blood vessels. Vessel wall (VW) MR imaging with blood vessel flow suppression and high spatial resolution may provide new insights into the detection of PD. However, there are no reports in the literature on the usefulness of VW MR imaging for the diagnosis of LN metastasis. It is demonstrated that PD of non-enlarged LNs in CE VR MR imaging of OSCC patients is useful for the diagnosis of metastatic LNs. VW MR imaging was significantly more sensitive in detecting PD of non-enlarged metastatic LNs than conventional TSE imaging on visual evaluation. Furthermore, it was found that the image contrast between PD and surrounding intranodal tissue in CE VW MR images was higher than that in conventional CE TSE images. In the correlation between imaging and histopathological findings of metastatic LNs, all LNs that exhibited PD on CE VW MR images were at an advanced histopathological metastatic stage. The pathology of PD was necrotic tissue with keratinization. The results indicated that PD in CE VW imaging is useful in diagnosing non-enlarged LNs at an advanced metastasis stage. The addition of VW MR imaging to conventional MR examination achieves higher diagnostic performance for non-enlarged metastatic LNs.

Development of the patient-based outcome instrument for foot and ankle: part 2: results from the second field survey: validity of the Outcome Instrument for the foot and ankle version 2.

BACKGROUND: The Clinical Outcomes Committee of the Japanese Society for Surgery of the Foot (JSSF) has conducted the second Field Survey of the Outcome Instrument for the Foot and Ankle version 2. METHODS: The survey of the Outcome Instrument version 2, which was composed of 43 items, was performed in 313 patients (154 men and 159 women) who had pathological conditions related to the foot and ankle. Optional sports items in the Outcome Instrument version 2 were analyzed in 123 patients. Internal consistency and construct validity of the Outcome Instrument version 2 were assessed. Correlation of the Outcome Instrument version 2 score with Short Form 36 (SF36) and JSSF scores was analyzed to evaluate criterion validity. RESULTS: Both the EFA and CFA demonstrated good alignment of questionnaire items with their intended subscales in most cases. Sports items were not clearly classified into subgroups. Therefore, it seemed reasonable to use those as a set of questions in a single subscale. The present subscales, having similar names as the SF36 subscales, were closely correlated with the respective subscales. In those cases, the magnitude of the correlation coefficient was >0.6 (p < 0.001) except the present subscale called General Health and Well-being. Comparison of the present scores with JSSF evaluation scores showed satisfactory results except in patients with rheumatoid arthritis. CONCLUSIONS: The Outcome Instrument version 2 demonstrated acceptable psychometric performances as outcome measures for patients with pathological conditions related to the foot and ankle. This outcome instrument would be helpful to evaluate patients with foot and/or ankle impairment. However, the analyses of the test-retest reliability and the influence of background factors such as age and gender, etc., on Outcome Instrument version 2 are needed in the third field survey.

Development of the patient-based outcome instrument for the foot and ankle. Part 1: project description and evaluation of the Outcome Instrument version 1.

BACKGROUND: The Clinical Outcomes Committee of the Japanese Society for Surgery of the Foot conducted a field survey using a novel foot and ankle outcome instrument. We report the development and evaluation of the Outcome Instrument version 1. MATERIALS AND METHODS: A total of 108 potential questions were extracted from literature published in the interval between 1990 and 2006. Tentative subscales proposed were "Degree of Foot Pain," "Foot Pain-related," "Physical Functioning and Daily Living," "Social Functioning" and "General Health and Well-being." After pre-testing in two different groups of patients, the Outcome Instrument version 1, which was composed of 46 items selected from the 108 questions, was administered to 256 patients (111 men and 145 women) with foot-and-ankle-related pathologic conditions and 243 healthy volunteers (125 men and 118 women). Cronbach's alpha coefficients were used for assessment of internal consistency of the instrument. Exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) were utilized for evaluation of construct validity. RESULTS: Neither a ceiling nor floor effect was observed in the responses from the patients. Significant differences were found in the responses to all of the questions between the patients and volunteers (P < 0.01 each). The Cronbach's alpha coefficients for each of the expected subscales indicated high reliability for most of the items and subscales. However, EFA extracted an additional subscale that should be interpreted as something related to shoe or shoe-fit. Further, both EFA and CFA indicated that "Degree of Foot Pain" and "Foot Pain-related" subscales were barely discernable with a factor correlation coefficient of 0.927. CONCLUSIONS: The Committee partly revised the instrument, and the new subscales are as follows: "Foot Pain and Pain-related," "Physical Functioning and Daily Living," "Social Functioning," "General Health and Well-being" and "Shoe-related." Evaluation of the Outcome Instrument version 2 will be reported in the following paper.

The Effect of Voluntary Exercise on Gut Microbiota in Partially Hydrolyzed Guar Gum Intake Mice under High-Fat Diet Feeding.

Although dietary fiber treatment alters the gut microbiota and its metabolite production, it is unclear whether or not exercise habits can have a supplemental effect on changes in gut microbiota in dietary fiber-treated mice. To clarify the supplemental effect of voluntary exercise on gut microbiota in partially hydrolyzed guar gum (PHGG), which is a soluble dietary fiber, treated mice under high-fat diet (HFD) feeding, 4-week-old male C57BL/6J mice (n = 80) were randomly divided into two dietary groups: the control-diet (CD) and HFD. Then, each dietary group was treated with or without PHGG, and with or without wheel running. After the experimental period, measurement of maximal oxygen consumption, a glucose tolerance test and fecal materials collection for analysis of gut microbiota were carried out. Voluntary exercise load in PHGG treatment under HFD feeding showed the supplemental effect of exercise on obesity (p < 0.01) and glucose tolerance (p < 0.01). Additionally, in both CD and HFD groups, voluntary exercise accelerated the decrease in the Firmicutes/Bacteroidetes ratio in mice fed with PHGG (p < 0.01). These findings suggest that voluntary exercise might activate the prevention of obesity and insulin resistance more via change in gut microbiota in mice administrated with PHGG.

Differential interference contrast microscope using photonic crystals for phase imaging and three-dimensional shape reconstruction.

We present a differential interference contrast microscope using photonic crystals capable of real-time capture of both phase and amplitude components independently without moving parts. Unlike previous methods using rotating polarizers to discriminate each component, we propose using a special camera equipped with an arrayed polarizer whose instant polarization measurement allows real-time acquisition of the phase gradient information. A two-image algorithm is used to reconstruct the phase two-dimensional distribution of biological samples from the gradient information with a transmission-type microscope. We also talk about deducing a sample's three-dimensional shape for a reflection-type microscope. The efficiency of the method is demonstrated experimentally.

Differences in muscle attachment proportion within the most common location of medial tibial stress syndrome in vivo.

INTRODUCTION: The medial tibial stress syndrome is one of the most common causes of running-related injuries. The primary study objective was to observe the attachment proportion of flexor digitorum longus and soleus, at the most common location of medial tibial stress syndrome, using ultrasonography, on a large cohort of young males and females to evaluate for gender-based anatomical differences. The secondary objective of this study was to investigate the relationship between the anatomical features and medial tibial stress syndrome. METHODS: In this study, we observed whether or not flexor digitorum longus and/or soleus attached at the middle and distal thirds of the medial margin of the tibia (most common location of medial tibial stress syndrome) using ultrasonography. History of medial tibial stress syndrome was defined by inquiries. RESULTS: The Chi2 tests showed that the attachment proportion of the soleus in female participants was significantly higher than that observed in male participants. In addition, Chi2 testing showed that there were no significant differences between attachment proportion of soleus of legs with history of medial tibial stress syndrome and legs without history of medial tibial stress syndrome, in both male and female participants. CONCLUSIONS: These results suggested that the anatomical features of flexor digitorum longus might be involved in medial tibial stress syndrome development, whereas the anatomical features of the soleus might not be involved in medial tibial stress syndrome development. LEVEL OF EVIDENCE: III, cross-sectional study.

An effective approach for iris recognition using phase-based image matching.

This paper presents an efficient algorithm for iris recognition using phase-based image matching--an image matching technique using phase components in 2D Discrete Fourier Transforms (DFTs) of given images. Experimental evaluation using CASIA iris image databases (versions 1.0 and 2.0) and Iris Challenge Evaluation (ICE) 2005 database clearly demonstrates that the use of phase components of iris images makes possible to achieve highly accurate iris recognition with a simple matching algorithm. This paper also discusses major implementation issues of our algorithm. In order to reduce the size of iris data and to prevent the visibility of iris images, we introduce the idea of 2D Fourier Phase Code (FPC) for representing iris information. The 2D FPC is particularly useful for implementing compact iris recognition devices using state-of-the-art Digital Signal Processing (DSP) technology.

New mathematical approach for approximating the baseline of F-waves using spreadsheet software.

OBJECTIVE: The aim of this study was to see if curved baselines of F-waves could be mathematically approximated with universal spreadsheet software. METHODS: The subjects were 3 healthy persons and 3 patients with cervical myelopathy. Supramaximal electrical stimuli were applied 200 times to the median nerve at the wrist. Compound muscle action potentials (CMAPs) of the abductor pollicis brevis were recorded. To make polynomial approximation equations that represent latter part of the M-waves, records without F-waves were analyzed. RESULTS: There were 193 CMAPs without F-waves out of all 1,200 records. Polynomial equations were made for each record. Determinant coefficients for all the approximation equations were greater than 0.998, and the overall standard deviation of the difference between original data and approximated value was 3.05 microV. CONCLUSIONS: Curved baselines of F-waves were represented by approximation curves. Baselines of the F-waves could be approximated as flat lines by subtracting calculated values from the original data. SIGNIFICANCE: This method was useful for analyzing waveforms of F-waves.