Multipoint surface electromyography measurement using bull's-eye electrodes for wide-area topographic analysis

BACKGROUND

Surface electromyography (sEMG) is primarily used to analyze individual and neighboring muscle activity. However, using a broader approach can enable simultaneous measurement of multiple muscles, which is essential for understanding muscular coordination. Using the "bull's-eye electrode," which allows bipolar derivation without directional dependence, enables wide-area multipoint sEMG measurements. This study aims to establish a multipoint measurement system and demonstrate its effectiveness and evaluates forearm fatigue and created topographic maps during a grasping task.

METHODS

Nine healthy adults with no recent arm injuries or illnesses participated in this study. They performed grasping tasks using their dominant hand, while bull's-eye electrodes recorded their muscle activity. To validate the effectiveness of the system, we calculated the root mean squares of muscle activity and entropy, an indicator of muscle activity distribution, and compared them over time.

RESULTS

The entropy analysis demonstrated a significant time-course effect with increased entropy over time, suggesting increased forearm muscle uniformity, which is possibly indicative of fatigue. Topographic maps visually displayed muscle activity, revealing notable intersubject variations.

DISCUSSION

Bull's-eye electrodes facilitated the capture of nine homogeneous muscle activity points, enabling the creation of topographic images. The entropy increased progressively, suggesting an adaptive muscle coordination response to fatigue. Despite some limitations, such as inadequate measurement of the forearm muscles' belly, the system is an unconventional measurement method.

CONCLUSION

This study established a robust system for wide-area multipoint sEMG measurements using a bull's-eye electrode setup. This system effectively evaluates muscle fatigue and provides a comprehensive topographic view of muscle activity. These results mark a significant step towards developing a future multichannel sEMG system with enhanced measurement points and improved wearability.

TRIAL REGISTRATION

This study was approved by the Ethics Committee of Chiba University Graduate School of Engineering (acceptance number: R4-12, Acceptance date: November 04, 2022).

Relationship between anxiety and monotonous task performance in response to local cooling: an experimental study in healthy young men

There are limited studies on monotonous task performance and its relationship with anxiety and stress traits. This study aimed to determine if local cooling exerts physiological effects and positively affects task performance. Ten male participants performed monotonous work for 24 min under control and local cooling conditions. We measured physiological arousal and anxiety using electroencephalography and the State-Trait Anxiety Inventory, respectively. The participants rated their drowsiness, the thermal sensation of the seat and whole-body thermal sensation. Despite the lack of significant differences in physiological arousal, the state anxiety score, which reflects the current stressful situation, was significantly lower in the local cooling condition. Therefore, cooling might help relieve stress during monotonous tasks, without impairing task performance. In addition, individuals with higher state anxiety scores tended to experience a faster increase in their arousal level. Thus, individual anxiety traits may modulate attentional resources during monotonous task performance.Practitioner summary: The study on topic related to monotonous task performance and its relationship with anxiety and stress traits is novel. Minimising negative emotions is key to monotonous task execution under stress. Individual anxiety might modulate resource allocation for monotonous task execution.

[A Case of Suspected Non-Occlusive Mesenteric Ischemia following Neoadjuvant Chemotherapy for Esophageal Cancer with an Extremely Poor Prognosis]

Non-occlusive mesenteric ischemia(NOMI)is defined as intestinal ischemia or necrosis with patency of the mesenteric arteries. Here, we report a case of suspected NOMI following neoadjuvant chemotherapy for esophageal cancer with an extremely poor prognosis. A 79-year-old man complained of weight loss and vomiting. Esophagogastroduodenoscopy revealed a tumor extending from the lower intrathoracic esophagus to the gastric cardia. He was diagnosed with esophageal cancer(small cell neuroendocrine carcinoma, T3(AD)N0M0, cStage Ⅱ)accordingly. He received cisplatin and etoposide as neoadjuvant chemotherapy. Tube feeding was initiated due to tumor stenosis. His weight increased rapidly by more than 8 kg on the second day of treatment. He did not display any signs of heart failure, and so continued chemotherapy in conjunction with diuretics. Upon completion of chemotherapy, his continued use of diuretics gradually reduced his weight. On day 7, the patient complained of nausea and experienced a decrease in blood pressure. Bicarbonate Ringer's solution was administered intravenously, but the patient lost consciousness after 3 hours. Plain computed tomography revealed massive gas collections in the portal vein, tumor wall, stomach, and ascending colon. NOMI was strongly suspected. His condition continued to deteriorate, until his demise several hours later. Here, we present the above-mentioned case and discuss the relevant literature.

Prediction of pathological response to preoperative chemotherapy for pancreatic ductal adenocarcinoma using 2-[18F]-fluoro-2-deoxy-d-glucose positron-emission tomography

AIM

To determine whether the pathological response to preoperative chemotherapy for pancreatic ductal adenocarcinoma (PDAC) can be predicted using 2-[18F]-fluoro-2-deoxy-d-glucose positron-emission tomography (F-18 FDG-PET).

MATERIALS AND METHODS

Twenty-eight patients with PDAC who underwent only neoadjuvant chemotherapy (NAC) before surgery were enrolled in the study. All patients had F-18 FDG-PET examinations before NAC. The resected specimen was pathologically evaluated according to the Classification of Pancreatic Carcinoma (7th edn). Patients were categorised into a non-response group and a response group based on the pathological findings. The non-response group (Grades 1a and 1b) showed ≤50% necrosis in the specimen, while the specimens of the response group (Grades 2-3) showed >50% necrosis. The maximum standardised uptake values (SUVmax) of the tumours on F-18 FDG-PET were measured. The mean values of SUVmax were compared between the two groups. The diagnostic performance of SUVmax in distinguishing the two groups was also evaluated using receiver operating characteristic analysis.

RESULTS

The mean SUVmax of the response group was higher than that of the non-response group (9.00 ± 1.78 versus 4.26 ± 2.35; p<0.001). The optimal cut-off value of SUVmax was 9.28 for distinguishing the two groups. The sensitivity, specificity, and accuracy for the prediction in the response group were 80%, 95.7%, and 92.9%, respectively.

CONCLUSIONS

SUVmax on F-18 FDG-PET may be useful as a biomarker to predict the pathological response to NAC in patients with PDAC.

A wearable lower extremity support for laparoscopic surgeons: A pilot study

Surgeons have increased physical stress during laparoscopic surgery due to operative site constraints. We developed a wearable device to reduce the physical stress on surgeons' lower extremities. The device mechanically facilitates maintaining a near-upright posture. The surgeon's knees are gently bent by a knee-joint locking mechanism, and fixing and releasing are performed independently on each side. The subjects were one female and two male surgeons, who wore the device during laparoscopic inguinal hernia repair or high anterior resection. Surface electromyogram (EMG) was conducted for both iliopsoas muscles. Control values were determined with the subject not wearing the device. Participants completed a post-procedure questionnaire. With the device, EMG activity had a tendency to decrease in the left iliopsoas muscle (P = .055), but it changed little on the right (P = .406). The post-procedure questionnaire showed an overall positive impression, although subjects reported some difficulty walking. This device decreases EMG activity and may improve a surgeon's work environment.

What is the significance of the traditional pinching mode of holding chopsticks?

Background

The purpose of this study was to clarify the influence of manipulation mode of chopsticks on the learning process, using assessment of task performance and electromyography, and to understand the significance of the traditional manipulation mode from the viewpoint of physiological anthropology. Previous studies have described two modes of manipulating chopsticks, the traditional pincers-pinching mode and the scissors-pinching mode.

Methods

We conducted experiments with two conditions of holding chopsticks: scissors mode and pincers mode. Eight subjects participated and were assigned to these modes, and they learned handling tasks in their assigned mode for 5 days with the non-dominant hand. We measured task execution times and conducted electromyography of the following muscles: first dorsalis interosseus, flexor pollicis brevis, flexor digiti minimi brevis, flexor digitorum superficialis, and extensor digitorum.

Results

The training effects were found in each mode. The pincers mode showed significantly shorter task performance times than did scissors mode. On electromyography, significant increases in activity of flexor digiti minimi brevis and tended an increase in flexor digitorum superficialis and a decrease in extensor digitorum occurred in pincers mode but not in scissors mode.

Conclusions

The traditional mode of holding chopsticks was associated with not only high task performance but also an advantage in terms of learning motor control.

Determining how different levels of indoor carbon dioxide affect human monotonous task performance and their effects on human activation states using a lab experiment: a tracking task

Different individuals respond differently to carbon dioxide (CO₂) levels in the local atmosphere. We aimed to determine whether brain activity changes with various CO₂ concentrations and whether this is correlated with heart rate and arterial oxygen saturation (SPO₂). We used electrocardiograms, SPO₂ measurements, electroencephalograms, and task performance metrics in various CO₂ concentrations and studied the changes in these metrics. We found that SPO₂ did not change in various CO₂ conditions; elevations in CO₂ up to 4000 ppm had no measurable influence on ventilation and SPO₂, suggesting no effect on monotonous task performance seen in terms of the alpha wave band rate. However, heart rate increased as early as within 15 min. We found that some individuals who naturally have lower SPO₂ values tended to undergo faster lowering of arousal level. Practitioner summary: SPO₂ may be an individual characteristic that affects the human ability to maintain concentration in monotonous tasks in enclosed spaces, such as driving a car. This study highlights the fact that different individuals respond differently to various CO₂ levels, based on SPO₂ levels, as manifested by decreased concentration and brain activity. Abbreviations: CO2: carbon dioxide; SPO2: arterial oxygen saturation; HR: heart rate; PaCO2: partial pressure of carbon dioxide; EEG: electroencephalography; ECG: electrocardiography; EOG: electrooculogram; HF: high-frequency; LF: low-frequency; ANOVA: analysis of variance; RRI: R-R interval ; Type 1: sensitive group; Type 2: non-sensitised group.

Contribution to oral and maxillary surgery and surgical technique of osteo-odontokeratoprosthesis in Japan

Osteo-odontokeratoprosthesis (OOKP) is a technique invented by Strampelli in 1963, in which the patient's own tooth root is used to support an optical cylinder. It uses an autologous tooth-bone-periodontal complex to mount an optical cylinder, which is stabilised by overlying autologous buccal mucosa. OOKP involves two, staged procedures done by ophthalmologists and oral surgeons, and the main contribution from the oral surgeon is during the first stage. To date we have done nine first-stage, and completed eight second-stage, OOKP operations in Japan with a mean follow-up of eight years and 11 months by modifying the original method of the oral surgery. All OOKP procedures were unilateral, and canines were selected as the donor teeth. Patients developed ocular blindness as a result of Stevens-Johnson syndrome, ocular cicatricial pemphigoid, and chemical and thermal burns to the cornea and ocular surface. All eight patients who completed the second stage have been stable, and there have been no major perioperative or postoperative oral complications. The patients' visual acuities were stable with no serious complications. Here we report the technical details of the oral contribution to OOKP.

A standing posture support device that reduces laparoscopic surgeons' occupational lower limb stress

BACKGROUND

We developed a surgical knee rest (SKR) that can be used to decrease the stress placed on the lower half of the body when surgeons work in the standing position. We tested the effectiveness of this device in the context of laparoscopic surgery.

MATERIAL AND METHODS

Five healthy, right-handed male surgeons participated, and we recorded surface electromyography (sEMG) signals from the two heads of the left and right gastrocnemius (Gc) muscles during laparoscopic resections of colorectal cancer. The outcome variable was the percentage of maximum Gc muscle effort generated, reported as percent maximal isometric voluntary contraction (%MVC), and this variable was compared between surgeries performed with and without use of the SKR. Assessment covered the first 100 min of surgery, subdivided into two 50-min periods.

RESULTS

Mean %MVC of the left Gc muscle for the full 100-min test period was significantly decreased when the SKR was used (p = .027, vs. SKR not used). Notably, mean %MVC of both Gc muscles was significantly decreased during the first 50 min of surgery (p = .008 and p = .0046).

CONCLUSION

The SKR is useful for decreasing physical stress incurred by laparoscopic surgeons when working in the standing position.

Subadditive responses to extremely short blue and green pulsed light on visual evoked potentials, pupillary constriction and electroretinograms

Background

The simultaneous exposure to blue and green light was reported to result in less melatonin suppression than monochromatic exposure to blue or green light. Here, we conducted an experiment using extremely short blue- and green-pulsed light to examine their visual and nonvisual effects on visual evoked potentials (VEPs), pupillary constriction, electroretinograms (ERGs), and subjective evaluations.

Methods

Twelve adult male subjects were exposed to three light conditions: blue-pulsed light (2.5-ms pulse width), green-pulsed light (2.5-ms pulse width), and simultaneous blue- and green-pulsed light with white background light. We measured the subject’s pupil diameter three times in each condition. Then, after 10 min of rest, the subject was exposed to the same three light conditions. We measured the averaged ERG and VEP during 210 pulsed-light exposures in each condition. We also determined subjective evaluations using a visual analog scale (VAS) method.

Results

The pupillary constriction during the simultaneous exposure to blue- and green-pulsed light was significantly lower than that during the blue-pulsed light exposure despite the double irradiance intensity of the combination. We also found that the b/|a| wave of the ERGs during the simultaneous exposure to blue- and green-pulsed light was lower than that during the blue-pulsed light exposure. We confirmed the subadditive response to pulsed light on pupillary constriction and ERG. However, the P100 of the VEPs during the blue-pulsed light were smaller than those during the simultaneous blue- and green-pulsed light and green-pulsed light, indicating that the P100 amplitude might depend on the luminance of light.

Conclusions

Our findings demonstrated the effect of the subadditive response to extremely short pulsed light on pupillary constriction and ERG responses. The effects on ipRGCs by the blue-pulsed light exposure are apparently reduced by the simultaneous irradiation of green light. The blue versus yellow (b/y) bipolar cells in the retina might be responsible for this phenomenon.

Human pupillary light reflex during successive irradiation with 1-ms blue- and green-pulsed light

Background

In the human retina, the contribution of intrinsically photosensitive retinal ganglion cells (ipRGCs) to the regulation of the pupillary response remains poorly understood. The objective of the current study was to determine the response dynamics of the pupillary light reflex to short, successive pulses of light. In order to better assess the roles of ipRGCs and cones, we used pulses of blue and green light.

Methods

Each participant was exposed to 1-ms blue (466 nm) and/or green (527 nm) light pulses simultaneously or separately, with inter-stimulus intervals (ISIs) of 0, 250, 500, 750, or 1000 ms. Pupil diameter was measured using an infrared camera system.

Results

We found that human pupillary light responses during simultaneous irradiation or successive irradiation with ISIs ≤ 250 ms were equivalent, though successive irradiation of blue- and green-pulsed light with ISIs ≥ 500 ms induced markedly increased pupillary constriction.

Conclusions

We propose that this result may be related to cell hyperpolarization that occurs in the retina just after the first light stimulus is turned off, with the threshold for this effect being between 250 and 500 ms in the human retina.

Erythropoietic protoporphyria a clinical and molecular study from Lebanon: Ferrochelatase a potential tumor suppressor gene in colon cancer

Erythropoietic protoporphyria (EPP) is a rare cutaneous and systemic disease caused by mutations in the ferrochelatase gene (FECH). The molecular underpinnings of EPP in Middle Eastern populations and relative to other ethnic groups secondary to increased consanguinity are unknown. To understand the molecular pathogenesis of Middle Eastern EPP, we surveyed clinicopathological and molecular features in 6 large consanguineous families from Lebanon and Syria presenting with cutaneous and systemic features consistent with EPP. We observed 30% increased liver disease and 20% elevated end-stage liver complications in our EPP cohort compared to EPP patients previously reported elsewhere. In addition, Middle Eastern EPP patients in our cohort exhibited uniquely an increased incidence of colon cancer. Sequence analysis revealed 2 novel non-synonymous FECH mutations in the studied families designated p.M294T and p.I230M. In addition, FECH activity was significantly decreased (6%) in fibroblasts obtained from sun-exposed sites in a patient with p.M294T mutation, whereas in sharp contrast, protected sites from the same patient exhibited 54% activity for the gene. We also found that sun-exposed fibroblasts, relative to sun-protected and control fibroblasts, exhibited suppressed growth and atypical morphology in vitro, and that these effects were alleviated when the cells were co-cultured with sun-protected fibroblasts. Our findings on the increased incidence of colon cancer in EPP patients prompted us to survey FECH expression patterns in cancer. Using publicly available microarray datasets we found that FECH mRNA was largely significantly decreased in colon adenocarcinomas relative to normal colon tissues. Our findings suggest that families with autosomal recessive EPP should be screened more extensively for systemic involvement including liver diseases and colon cancer, and point to a previously unknown yet plausible tumor suppressor role for FECH in colon malignancy.

A novel mutation in the RSPO4 gene in a patient with autosomal recessive anonychia

The Wnt signalling pathway is a major pathway involved in the embryogenic development of the various organs of the body. Appropriate signalling in this pathway relies on the proper functioning of several proteins including the R-spondin family of proteins. Deactivating mutations in R-spondin 4 are associated with anonychia. We present the case of a 26-year-old man presenting with anonychia of the 20 nails, which had been present since birth. Using genetic studies, we identified a novel nonsense mutation, c.164-165TC>AA, characterized by two consecutive mismatch bases. To our knowledge, this mutation is the first to be reported in R-spondin 4 in a Lebanese population. Evaluating new patients with anonychia provides fruitful clinical and molecular findings.

Characterization of pediatric Philadelphia-negative B-cell precursor acute lymphoblastic leukemia with kinase fusions in Japan

Recent studies revealed that a substantial proportion of patients with high-risk B-cell precursor acute lymphoblastic leukemia (BCP-ALL) harbor fusions involving tyrosine kinase and cytokine receptors, such as ABL1, PDGFRB, JAK2 and CRLF2, which are targeted by tyrosine kinase inhibitors (TKIs). In the present study, transcriptome analysis or multiplex reverse transcriptase–PCR analysis of 373 BCP-ALL patients without recurrent genetic abnormalities identified 29 patients with kinase fusions. Clinically, male predominance (male/female: 22/7), older age at onset (mean age at onset: 8.8 years) and a high white blood cell count at diagnosis (mean: 94 200/μl) reflected the predominance of National Cancer Institute high-risk (NCI-HR) patients (NCI-standard risk/HR: 8/21). Genetic analysis identified three patients with ABL1 rearrangements, eight with PDGFRB rearrangements, two with JAK2 rearrangements, three with IgH-EPOR and one with NCOR1-LYN. Of the 14 patients with CRLF2 rearrangements, two harbored IgH-EPOR and PDGFRB rearrangements. IKZF1 deletion was present in 16 of the 22 patients. The 5-year event-free and overall survival rates were 48.6±9.7% and 73.5±8.6%, respectively. The outcome was not satisfactory without sophisticated minimal residual disease-based stratification. Furthermore, the efficacy of TKIs combined with conventional chemotherapy without allogeneic hematopoietic stem cell transplantation in this cohort should be determined.

Spermatogenesis in tumor-bearing testes in germ cell testicular cancer patients

STUDY QUESTION

What are the factors that might indicate a greater likelihood of success in oncologic testicular sperm extraction (onco-TESE)?

SUMMARY ANSWER

Smaller tumor diameter and greater noncancerous testicular tissue width (NCTW) are positive predictors of spermatogenesis in patients with testicular germ cell tumors (TGCTs).

WHAT IS KNOWN ALREADY

Onco-TESE is a key modality for fertility preservation in cases of inadequate pretreatment sperm collection and azoospermic men with testicular cancer. TGCTs are known to reduce sperm quality such that ∼ 10% of these patients are azoospermic, making surgical TESE at the same time as orchiectomy their only means of fertility preservation.

STUDY DESIGN, SIZE, DURATION

This study is a retrospective analysis performed in a single university hospital from 2002 to 2014.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Participants were 102 male patients (104 testes) who underwent inguinal orchiectomy and were diagnosed with a germinoma. In each specimen, the Johnsen Score Count (JSC) in seminiferous tubules at each established distance from the tumor margin (1, 2.5, 5, 7.5, 10 and 12.5 mm) was determined. We analyzed the relations between age, tumor histopathologic type, tumor size (maximum diameter), distance from the tumor, non-tumor tissue width and JSC.

MAIN RESULTS AND THE ROLE OF CHANCE

The 104 specimens consisted of 78 seminomas and 26 non-seminomatous TGCTs. The mean ± SD JSC was 4.7 ± 2.4 in seminomas and 3.9 ± 2.5 in non-seminomatous germ cell tumors, with no significant difference between the two subtypes. Single regression analysis showed that tumor diameter was significantly negatively correlated with spermatogenesis (RC = -0.422, P < 0.001). Multiple linear regression analysis also showed that tumor diameter had a negative influence on spermatogenesis (RC = -0.437, P < 0.001). The greater the distance the seminiferous tubules from the tumor, the better the preservation of spermatogenesis. Mature spermatozoa were identified in 93.0% of patients with a NCTW ≥ 7.5 mm and in 41.3% of those with NCTW < 7.5 mm (P < 0.001).

LIMITATIONS, REASONS FOR CAUTION

Study data were obtained retrospectively, which might have affected the quality of data. We were unable to compare spermatogenesis determined using preoperative seminograms with that determined histopathologically. It was not possible to evaluate spermatogenesis in the total volume of noncancerous testicular tissue.

WIDER IMPLICATIONS OF THE FINDINGS

When Onco-TESE is conducted at sites distant from tumors, the rate of sperm extraction is high and contamination by tumor cells can be prevented. By measuring non-testicular cancerous margin before the operation, the possibility of sperm extraction can be predicted and biopsy of the contralateral testis can be considered based on the results.

Verification of impact of morning showering and mist sauna bathing on human physiological functions and work efficiency during the day

Recently, a growing number in Japan are switching to taking baths in the morning (morning bathing). However, the effects of the morning bathing on human physiological functions and work efficiency have not yet been revealed. Then, we hypothesized that the effect of morning bathing on physiological functions would be different from those of night bathing. In this study, we measured the physiological functions and work efficiency during the day following the morning bathing (7:10-7:20) including showering, mist sauna bathing, and no bathing as a control. Ten male healthy young adults participated in this study as the subjects. We evaluated the rectal temperature (Tre), skin temperature (Tsk), heart rate (HR), heart rate variability (HRV), blood pressure (BP), the relative power density of the alpha wave (α-wave ratio) of electroencephalogram, alpha attenuation coefficient (AAC), and the error rate of the task performance. As a result, we found that the HR after the mist sauna bathing was significantly lower than those after no bathing rest 3 (11:00). Furthermore, we verified that the α-wave ratio of the Pz after the mist sauna bathing was significantly lower than those after no bathing during the task 6 (15:00). On the other hand, the α-wave ratio of the Pz after the mist sauna bathing was significantly higher than those after showering during the rest 3 (11:00). Tsk after the mist sauna bathing was higher than those after the showering at 9:00 and 15:00. In addition, the error rate of the task performance after the mist sauna bathing was lower than those after no bathing and showering at 14:00. This study concludes that a morning mist sauna is safe and maintains both skin temperature compared to other bathing methods. Moreover, it is presumed that the morning mist sauna bathing improves work efficiency comparing other bathing methods during the task period of the day following the morning bathing.

Effects of horizontal console position on operator muscular stress during cardiac ultrasonic diagnosis

Ultrasound examinations tend to put sonographers in unnatural postures, which may lead to musculoskeletal disorders. In order to address this issue, in this study, we focused on the horizontal position of the console of a diagnostic ultrasound system to quantitatively assess the influence of the work plane position on musculoskeletal stress cardiac ultrasonic diagnosis in the bed-sitting position. Five subjects were asked to simulate a scanning task that involved touching five points on the console, setting the work plane at different positions in the space. Electromyogram of each part of the body indicated that the least stressful position of the left hand was about 350 mm from the center of the trunk in the longitudinal (front-rear) direction and 100 mm left from the center of the trunk in the lateral (left-right) direction. It is necessary to rotate the console in front of the operator for this purpose.

Ergonomic design and evaluation of new surgical scissors

The purpose of this study is to design a new surgical scissors handle and determine its effectiveness with various usability indices. A new scissors handle was designed that retains the professional grip but has the shapes of the eye rings modified to fit the thumb and ring finger and finger rests for the index and little finger. The newly designed scissors and traditional scissors were compared by electromyography, subjective evaluation and task performance in experiments using cutting and peeling tasks. The newly designed scissors reduced muscle load in both hand during cutting by the closing action, and reduced the muscle load in the left hand during peeling by the opening action through active use of the right hand. In evaluation by surgeons, task performance improved in addition to the decrease in muscle load. The newly designed scissors used in this study demonstrated high usability.

PRACTITIONER SUMMARY

A new scissors handle was designed that has the eye rings modified to fit the thumb and ring finger. The newly designed scissors reduced muscle load and enabled active use of the right hand. In evaluation by surgeons, task performance improved in addition to the decrease in muscle load.

Self-awareness of fast eating and its impact on diagnostic components of metabolic syndrome among middle-aged Japanese males and females

OBJECTIVE

The aim of the present study was to examine the association between subjects with self-awareness of fast eating and diagnostic components of metabolic syndrome in Japanese middle-aged male and female.

PATIENTS AND METHODS

Subjects consisted of 3208 males (average age 50.6 years) and 2055 females (average age 50.0 years). Associations between subjects with self-awareness of fast eating and multiple components of metabolic syndrome (waist circumference, body mass index [BMI], blood pressure, and related blood sample tests) were evaluated.

RESULTS

Significantly more males (57.7%) acknowledged themselves as "fast eater" than females (46.5%). Self-reported fast eaters showed significantly elevated body weight, BMI, and waist circumference in both genders. However, only male self-reported fast eaters showed high levels of blood pressure, fasting blood glucose, uric acid, and low-density lipoprotein (LDL)-cholesterol.

CONCLUSION

Fast eating is associated with diagnostic components of metabolic syndrome. The effect of acknowledging themselves as fast eater presents a higher impact on males than on females in the middle-aged Japanese population. The present study indicates that finding subjects with self-awareness of fast eating may lead to the prevention of developing metabolic syndrome.

THE INFLUENCE OF LATERALITY ON DIFFERENT PATTERNS OF ASYMMETRICAL FOOT PRESSURE AND MUSCLE ACTIVATION DURING A GAIT CYCLE IN MANUAL PUSHING

This study investigated laterality of manual pushing during a gait cycle by measuring pushing force, muscular activation and foot pressure. Subjects were 17 healthy young adult males; (11 right-handed [RH], and 6 left-handed [LH]). They pushed a force plate while walking on a treadmill at 1.5, 3, and 4 km/h. Electromyogram (EMG) data were collected bilaterally from the tibialis anterior, soleus, lumbar erector spinae and triceps brachii. To measure foot pressure, ten pressure sensors were attached bilaterally on five points of the sole. Symmetry assessment was performed by comparing bilateral data and cross-correlation function (CCF). Gait cycle duration was found to be symmetrical in all conditions. LH subjects demonstrated asymmetry in calcaneus contact duration to control ankle flexion, whereas RH were symmetrical. Velocity affected tibialis anterior muscle time lag and soleus muscle CCF coefficients, mainly in LH. We found that triceps brachii muscle CCF coefficients in LH subjects were affected by increasing velocity. Results indicated that LH and RH did not mirror each other, since both had distinct characteristics. Furthermore these asymmetries were not strictly associated with the preferred side, indicating that generalisation of preferred side to whole-body coordination should be avoided, since we could not separate one side from the other.

Quantification of changes in metamorphopsia and retinal contraction in eyes with spontaneous separation of idiopathic epiretinal membrane

BACKGROUND

To quantify changes in metamorphopsia and retinal contraction in eyes with idiopathic epiretinal membrane (ERM) before and after a spontaneous separation of ERM.

METHODS

Among 92 eyes of 92 patients with idiopathic ERM who were followed up at our hospital, 5 eyes of 5 patients had experienced a spontaneous separation of ERM during the follow-up period. Patient's metamorphopsia was assessed horizontally and vertically by a metamorphopsia chart developed by our group, M-CHARTS, to obtain the horizontal (MH) and vertical (MV) metamorphopsia scores. Difference in the scores before and after the membrane separation represents change in patient's metamorphopsia. Changes in retinal contraction were also evaluated horizontally and vertically with our original software for fundus image analysis. The difference between M-CHARTS scores and distances of retinal vessel movements with before and after membrane separation were measured.

RESULTS

All five subjects showed a decrease in the retinal contraction. Improved visual acuity was observed in three subjects, and no change was seen in the other two. Four subjects obtained better metamorphopsia scores after the membrane separation, while the other one was not detected with metamorphopsia by M-CHARTS either before or after the separation. In subjects with an improved MV, horizontal retinal movement was seen larger than the vertical movement. Similarly, the subjects with an improved MH indicated a larger vertical retinal movement than the horizontal movement.

CONCLUSIONS

The direction of patient's metamorphopsia closely associated with the direction of retinal contraction before and after a spontaneous separation of ERM.

Sustaining biological welfare for our future through consistent science

Physiological anthropology presently covers a very broad range of human knowledge and engineering technologies. This study reviews scientific inconsistencies within a variety of areas: sitting posture; negative air ions; oxygen inhalation; alpha brain waves induced by music and ultrasound; 1/f fluctuations; the evaluation of feelings using surface electroencephalography; Kansei; universal design; and anti-stress issues. We found that the inconsistencies within these areas indicate the importance of integrative thinking and the need to maintain the perspective on the biological benefit to humanity. Analytical science divides human physiological functions into discrete details, although individuals comprise a unified collection of whole-body functions. Such disparate considerations contribute to the misunderstanding of physiological functions and the misevaluation of positive and negative values for humankind. Research related to human health will, in future, depend on the concept of maintaining physiological functions based on consistent science and on sustaining human health to maintain biological welfare in future generations.

Functional studies for the TRAF6 mutation associated with hypohidrotic ectodermal dysplasia

BACKGROUND

Hypohidrotic ectodermal dysplasia (HED) is a rare condition characterized by hypotrichosis, hypohidrosis and hypodontia. A de novo heterozygous mutation in the tumour necrosis factor receptor-associated factor 6 gene (TRAF6) was recently identified in a patient with HED, while functional consequences resulting from the mutation remained unknown.

OBJECTIVES

To determine the mechanism by which the TRAF6 mutation results in HED.

METHODS

We performed coimmunoprecipitation (co-IP) studies to determine whether the mutation would affect the interaction of TRAF6 with transforming growth factor β-activated kinase 1 (TAK1), TAK1-binding protein 2 (TAB 2) and ectodysplasin-A receptor-associated death domain protein (EDARADD). We then performed co-IP and glutathione S-transferase-pulldown assays to determine the TRAF6 binding sequences in EDARADD. In addition, we analysed the effect of the mutant TRAF6 protein on the affinity between wild-type TRAF6 and EDARADD, as well as on EDARADD-mediated nuclear factor (NF)-κB activation.

RESULTS

The mutant TRAF6 protein was capable of forming a complex with TAK1 and TAB 2 in a similar way to wild-type TRAF6. However, the mutant TRAF6 protein completely lost the affinity to EDARADD, while the wild-type TRAF6 bound to the N-terminal domain of EDARADD. Furthermore, the mutant TRAF6 inhibited the interaction between the wild-type TRAF6 and EDARADD, and also potentially reduced the EDARADD-mediated NF-κB activity.

CONCLUSIONS

We conclude that the mutant TRAF6 protein shows a dominant negative effect against the wild-type TRAF6 protein, which is predicted to affect the EDARADD-mediated activation of NF-κB during the development of ectoderm-derived organs, and to lead to the HED phenotype.

Physiological functions of the effects of the different bathing method on recovery from local muscle fatigue

BACKGROUND

Recently, mist saunas have been used in the home as a new bathing style in Japan. However, there are still few reports on the effects of bathing methods on recovery from muscle fatigue. Furthermore, the effect of mist sauna bathing on human physiological function has not yet been revealed. Therefore, we measured the physiological effects of bathing methods including the mist sauna on recovery from muscle fatigue.

METHODS

The bathing methods studied included four conditions: full immersion bath, shower, mist sauna, and no bathing as a control. Ten men participated in this study. The participants completed four consecutive sessions: a 30-min rest period, a 10-min all out elbow flexion task period, a 10-min bathing period, and a 10-min recovery period. We evaluated the mean power frequency (MNF) of the electromyogram (EMG), rectal temperature (Tre), skin temperature (Tsk), skin blood flow (SBF), concentration of oxygenated hemoglobin (O2Hb), and subjective evaluation.

RESULTS

We found that the MNF under the full immersion bath condition was significantly higher than those under the other conditions. Furthermore, Tre, SBF, and O2Hb under the full immersion bath condition were significantly higher than under the other conditions.

CONCLUSIONS

Following the results for the full immersion bath condition, the SBF and O2Hb of the mist sauna condition were significantly higher than those for the shower and no bathing conditions. These results suggest that full immersion bath and mist sauna are effective in facilitating recovery from muscle fatigue.