Contractile performance of cardiac tissue reconstructed in vitro is markedly lower than that of in vivo tissue. In spite that polyunsaturated fatty acids (PUFAs) play crucial roles in cardiomyocyte contraction, conventional culture medium contains little lipids. In the present study, we supplemented arachidonic (AA) or docosahexaenoic (DHA) acid in medium in which cardiomyocytes harvested from fetal rats were cultured, and found that contractile performance in AA- or DHA-supplemented cardiomyocytes was higher than that in non-supplemented cells. Supplemented PUFA content in cardiomyocytes in culture was dose-dependent, and the maximum contraction performance was obtained when 50 μM AA or 20 μM DHA was supplemented. With that concentration of AA or DHA, the supplemented PUFA content was close to that of myocardium in neonatal rats. The results suggest that proper supplementation of AA and DHA may be important to increase contractile performance in cultured cardiomyocytes.

Actin filaments play a major role for maintain the cell morphology and sensing mechanical stresses in many types of cell. It is well known that cytoskeletal structure and proteins in and on cells are fluctuating with the thermal effect. Here, we have observed very small fluctuation of actin filaments in living cell. Actin filaments in NIH3T3 were visualized with Lifeact-GFP fusion protein. The fluorescent images were taken with the forcal microscopy 10 images every second. From the sequential images, we analyzed the width and frequency of actin fluctuation. The frequency of actin fluctuation was about 2.3 Hz and the width was 0.3 μm. It is possible that these values are affected with mechanical conditions, such as flow and the change of temperature. We continue to analyze the actin fluctuation under several types of mechanical conditions.

We have been developing a surgical navigation system to support a surgeon to identify the anatomical orientation. Its first prototype was designed in 2004 and clinically tested in 2006. During this decade, we have utilized it in one hundred clinical cases. Learned through trial and error, it was found that this system needed to improve the usability and the reliability in registration process to show valuable information for surgery. Our improved system was approved to use for clinical pre-trial from Hospital Ethics Committee of Tokyo Women's Medical University (160402), and it was utilized for six cases from June 2016 to January 2017. The new system worked suitably compared with the former one. As for spending time on the new system, it took 9.8±1.7 minutes before thoracotomy and 6.4±1.5 minutes after adhesiolysis. Target arteries were determined smoothly in all cases. We hope that widespread use of the system would be promoted.

Prevention of medical malpractices related with surgical instruments is required. We have developed a new system that can obtain the information of surgical instruments, using radio-frequency identification (RFID) tags, during surgery in an operation room. The objective of this study was to investigate its accuracy. The number of surgical instruments was counted by visual observation as well as the system, and results were compared to make sure the accuracy of the counting system. The experiments were conducted during inguinal hernia surgeries and mastectomies.An acquisition rate was around 96% because the RFID tags were sometimes placed out of the radio communication range on the system. However, the system could recognize RFID tags when they were covered by blood because the system use radio communication technology. This study has proved that the system can obtain accurate information of surgical instruments during surgery.

Ontological investigation has been applied to the health care field in several areas, such as disease terminology and clinical guidelines. However, few reports have adopted an ontological approach to clinical procedures. This study attempts ontological analysis to the procedure of endoscopy, and feasibility and problems were discussed. Physician's actions during gastrointestinal endoscopy were decomposed by an ontological approach. The endoscopic procedure was classified and flows of the procedure are described using a river-flow model. The procedures of endoscopy were successfully described within ontological concepts. Ontological analysis and description of surgical procedure can be applied in many areas, including medical training, ergonomic workflow management and development of surgical robotics. However, difficulties remain in mapping concurrencies and repetitive processing. Complicated and troublesome procedures of ontological analysis should be improved. Also needs for computer software that provides simple and practical analysis of clinical procedures was shown in this study.

Currently, distal pancreatectomy using a stapler is often performed as a treatment for pancreatic cancer. However, leakage of pancreatic juice may occur in this surgery. One of the reasons of this is mentioned pancreatic membrane break due to stapler compression. Therefore, in order to observe the break of membrane and optimize the compression parameter of stapler that can suppress leakage of pancreatic juice, force and fluorescence measurement system during compression was developed. In compression test, difference of reaction force was confirmed when changing the compression speed. Fluorescence observation made it possible to visualize the site of membrane breaking on fundamental evaluation. In the future, examination of relation between various compression parameters and membrane break in combined experimental system will be performed.

Radiotherapy planning requires calculation of cumulative dose distribution of a series of treatment planning. In the treatment of the uterus, a radioactive tool is inserted into the uterus which causes the uterus to deform. We aimed at developing deformable image registration to support treatment planning considering a physical constraint of the uterus by the tool. Intensity-based deformable image registration has been intensively studied. However, the physical constraint by the tool could not be considered. In this study, we applied a finite element method to intensity-based image registration to consider physical characteristics. The center lines are extracted from the uterus and radioactive tool automatically. The experimental results using a phantom and patients' data revealed that the proposed method is relatively effective when the uterus deforms largely.

We have developed a highly accurate, three-dimensional, local-positioning system to be applied to novel medical-training materials such as biological models. This system consists of a main body having 12 high-sensitivity magnetic sensors (Seiko NPC SA3600 AP) and a signal processing circuit of three field-programmable gate arrays (FPGAs), three markers indicating positions, and a personal computer for visualization. The position accuracy and response are about ±0.5 mm (measurement range: 100 mm) and about 0.05 s. Also, the main body is compatible with bluetooth, and it is possible to wirelessly connect (within about 10 m) with a personal computer. The dimensions of the main body, power consumption, and marker size are 300 mm ×200 mm ×30 mm, about 24 W, and ϕ5 mm ×30 mm. Medical students should improve the educational benefits by using the system.

Conventional SNGFR (single nephron glomerular filtration rate) measurement by micropuncture needs sampling fluids from a glomerulus, proximal tubule and distal tubule. Thus in-vio measurement has been impossible. The purpose of this study was to demonstrate in-vivo measurement of SNGFR by confocal laser microscopy. We used early DM Wistar rats induced by tail vein streptozotocin injection. Under anaesthesia, the kidney was exposed. Tubules were observed with a confocal microscope and 10 kDa extrans conjugated with Texas Red was administered. The urinary flow volumes between any given two points were measured from the video images and were converted to volumes for 1 minute, SNGFR. The values were found higher in diabetic rats than in control rats (19.1± 0.2 nl/min, 28.1± 0.2 nl/min)( p<0.05). SNGFR values were in the same order of reported values by the conventional method. We were able to demonstrate the hyperfiltration in early diabetes by SNGFR under in-vivo conditions.

Mammals and birds have 4-chambered hearts and fully separated pulmonary and systemic circulation. Cardiac tissues in extant vertebrates are divided into two types, compact and spongy myocardium, which are associated with blood supply systems i.e. coronary and sinusoidal circulation respectively. Mammals and birds have the hearts with coronary circulation with diastolic predominant flow due to ventricular compression during systole. We examined whether compact myocardium had a stiffer mechanical property compared with spongy myocardium to maintain diastolic coronary flow, and gene and amino acid sequence of molecular spring connectin that regulates ventricular mechanical property.The hearts of rats and chickens were significantly stiffer than those of frogs. The lengths of elastic segments of connectin in mice and chickens were shorter, with different regulatory mechanisms, than those in frogs . These results showed that mammals and birds evolved the strong 4-chambered hearts independently in adapting to oxygen environment.

Mechanical stimuli by a probe were applied to myocardial cell aggregates in vitro. The stimulus was given periodically and its motion was mimicking the actual contraction-relaxation motion of spontaneous beating by a cell aggregate. We investigated the effect of the external stimuli on spontaneous beating of cell aggregates in short-term at room temperature and in long-term under culture conditions. At room temperature, myocardial cell aggregates were sensitive to the stimuli and the aggregate's spontaneous interbeat interval (IBI) dramatically changed in time. In contrast, the long-term periodic stimuli tended aggregates to synchronize their beating with the stimulus frequencies by 24h. Finally, we would discuss the biological responses under long-term mechanical stimuli in culture conditions.

We have been studying adverse effect of ultrasound exposure on pulsation of the heart using cardiomyocytes isolated from neonatal rats. Our previous study used cardiac myocytes cultured on a cover slip scaffold; however, the stiffness of the underlying layer is very different from that in in vivo conditions. In this study, cardiomyocytes were cultured on a soft gel scaffold, and their mechanosensitivity was compared with those cultured on a coverslip scaffold. In the experimental results, significant difference was found in the shape indices that represent circularity of cells (gel, 0.29 ± 0.08; cover slip, 0.11 ± 0.04), indicating that cytoskeleton is less developed in the cells cultured on the gel scaffold. Furthermore, a threshold of cycle numbers to induce pulsation disruption is about 10 times higher in the cardiomyocytes culltured on gel scaffold, suggesting the dependence of mechanosensitivity of cardiomyocytes on development of their cytoskeleton.

Shock wave irradiations alter mitochondrial morphologies. In previous studies, shock waves with large energy intensities with peak pressures around 70 MPa were irradiated on cells to observe those alterations. Those alterations were investigated to understand side effects of Extracorporeal Shock Wave Lithotripsy (ESWL). In these 10 years, shock waves with small energy intensity, around 1/10 of those in ESWL, have been demonstrated to induce cellular effects. In our research, shock waves with further small intensity, 1/100 of those in ESWL, are also possible to induce cellular effects. In this study, it has been questioned whether those shock waves with further small intensity could affect mitochondrial morphologies. As results, mitochondrial morphologies altered dependent on actin cytoskeletons.