Flow Velocity in Common Carotid Artery

A significant blood flow disruption as seen in cardiovascular diseases and disorders is related to hemodynamic dysfunction. Gender influences the arterial hemodynamic functions. Understanding of gender-related differences in blood flow and pressure is crucial in the prevalence and burden of cardiovascular disease. This chapter presents about characteristic profile of carotid flow velocities to extend the fundamental understanding of arterial hemodynamic functions in gender differences. Comparison of both synchronized carotid blood flow velocity and blood pressures at normodynamics state are introduced to contribute to targeted therapeutic goal based on gender. Gender-related differences in body size has influenced on arterial hemodynamics in carotid artery. Body height has influenced on systolic blood pressure, pulse pressure, wave reflection, pulse wave velocity in carotid artery. Carotid blood flow velocities are largely accounted for not only body height but also body weight. The predictors for modulating blood flow velocities were not only limited to age, but also influenced by several body compositions that largely accounted for the gender-related differences including visceral fat, muscle mass and total body fat. These data may useful to effective prevention and management of cardiovascular disease by considering the gender-difference

Engineered Meniscus Scaffolds using Sonication Decellularization Treatment System

Meniscus located in the weight-bearing area responsible for the movement and functions of the knee. However, the frequent injuries within the avascular region of meniscus have lack of healing capability. Thus, the emerging decellularized scaffolds serve as one the interventions for the regeneration of new tissues to treat early degenerative joint disease. The aim of this study is to investigate the effectiveness of sonication treatment system in decellularization of meniscus tissues. The decellularization process was conducted in 40 kHz frequency with 0.1% SDS solution for 10 hours and proceeds with five days washing process. The decellularization efficiency was evaluated through histology, gel electrophoresis and biochemical assays to observe the cellular components removal and preservation of extracellular matrix (ECM). Compared to the control group, the histological evaluation of sonication decellularized scaffolds based on staining van Gieson showed complete removal of cellular components. Picrosirius red and Safranin O/fast green staining revealed the well preservation of the distribution of collagen and glycosaminoglycan networks (GAGs) in sonication decellularized scaffolds and no visible of DNA bands in the electrophoresis of agarose gel. Biochemical assessment for DNA quantification illustrated a significant decrement of DNA residues and GAGs for sonication decellularized scaffolds while maintained in collagen content. Based on the results, it can be deduced that sonication decellularization treatment system successfully prepared scaffolds with low cellular contents and maintained extracellular matrix components. Therefore, sonication decellularization treatment system can serve as one of the potential physical decellularization method in tissue engineering and regenerative medicine fields

Simulation of Neural Behavior

The brain is an organ that takes the central role in advanced information processing. There exist great many neurons in our brain, which build complicated neural networks. All information processing in the brain is accomplished by neural activity in the form of neural oscillations. In order to understand the mechanisms of information processing, it is necessary to clarify functions of neurons and neural networks. Although the current progress of experiment technology is remarkable, only experiments by themselves cannot uncover the behavior of only a single neuron. Computational neuroscience is a research field, which fills up the deficiency in experiments. By modeling the essential features of a neuron or a neural network, we can analyze their fundamental properties by computer simulation. In this chapter, one aspect of computational neuroscience is described. At the first, the cell membrane and a neuron can be modeled by using an RC circuit. Next, the Hodgkin-Huxley model is introduced, which has the function of generation of action potentials. Furthermore, many neurons show the subthreshold resonance phenomena, and the cell membrane is necessary to be modeled by an RLC circuit. Finally, some simulation results are shown, and properties of such neuronal behaviors are discussed

Structural integrity of aortic scaffolds decellularized by sonication decellularization system

Sonication decellularization technique has shown effectiveness to remove all the cellular components by the disruption of the cell membranes and removal of the cell debris to prepare the bioscaffolds. However, it is important to confirm whether this technique does not have a detrimental effect on elastin and collagen in bioscaffolds. The objectives of this study are to evaluate the structural integrity of bioscaffolds using histological staining and quantitatively collagen and elastin measurement. Aortic tissues were sonicated in 0.1% SDS for 10 hours at the frequency of 170 kHz with the power output of 15W and washed in Phosphate Buffer Solution (PBS) for 5 days. Then the sonicated aortic tissues were evaluated by Hematoxylin & Eosin (H&E) staining for cell removal analysis, Verhoeff-van Gieson (VVG) staining for visualizing elastin and Picrosirius Red (PSR) staining for visualizing collagen. The collagen and elastic fibres were semi-quantified by ImageJ software. The results showed that sonication decellularization system can remove all the cellular components while maintaining the structural integrity of elastin and collagen on bioscaffolds. This study indicates that sonication decellularization system could remove all cellular components and maintain the structure of the extracellular matrix

Bio-Engineered Meniscus for Tissue Engineering

Meniscus plays fundamental roles in the knee mechanisms and functions. It acts as a shock absorber where it enables even distribution of forces, and also lubricates knee joints. Meniscal injuries could result to the onset of degenerative osteoarthritis if proper treatments are delayed. To date, treatment of meniscal injuries are more towards conservative methods and surgical approach commonly known as meniscectomy. Attempts to develop scaffolds for meniscus implants from synthetic and biological sources have been done in the recent years. This approach involves a multidisciplinary study known as tissue engineering and regenerative medicine. It involves the combination of three crucial aspects; the choice of chondrogenic/stem cells, bioscaffolds and favourable environmental factors such as growth factors. This chapter discusses and highlights on the currently available meniscal scaffolds that have been explored before. Focus is also directed on the potential of decellularized extracellular matrix (ECM), prepared through sonication treatment that produced scaffolds which mimics natural meniscus. The evaluation of decellularized scaffolds was portrayed through recellularization using cells namely chondrocytes, fibrochondrocytes and stem cells in order to regenerate new functional tissue. In short, this chapter serves as a representation of current approaches aiming in bio-engineering the meniscal scaffolds as meniscus tissue replacement

In vitro recellularization of aorta scaffolds prepared by sonication treatment

Sonication treatment is used in the preparation of bioscaffolds that was able to support repopulation of vascular smooth muscle cells (VSMCs) upon cell-seeding. The aim of this study is to investigate the ability of sonicatedly decellularized tissue to repopulate VSMCs after 6 days of cell-seeding. In this study, sample of aorta tissues are decellularized by sonication treatment in 0.1% and 2% sodium dodecyl sulfate (SDS) detergent for 10 hours. It was followed by washing process with PBS solution for 5 days. Decellularized aorta tissues are then cell seeded with VSMCs by static seeding in 96-well plate containing Dulbecco's Modified Eagle Medium (DMEM) at 37°C. The infiltrations of VSMCs onto decellularized tissues are evaluated by comparison of Hematoxylin-Eosin (H-E) staining at 0 and 6 days of cell-seeding. The histological results of cell-seeding showed that VSMCs are able to infiltrate onto the decellularized tissues. From the results, sonicatedly decellularized tissue treated in 0.1% and 2% SDS, seeded with VSMCs showed infiltration depth of 0.43 mm and 0.35 mm, respectively. Hence, a sonicated decellularized tissue treated with 0.1% and 2% SDS was shown to support the repopulation of VSMCs

Decellularized bovine meniscus in morphological assessment prior to bioscaffold preparation

Decellularization is a process of tissue treatment targeting cell removal. Sonication system was developed in order to decellularize meniscus tissues. The samples were sonicated in 0.1% sodium dodecyl sulphate (SDS) for 10 hours and at 40 kHz ultrasound frequency. All the samples were structurally examined using van Gieson, Picrosirius red, Safranin-O/Fast green staining, and scanning electron microscopic (SEM) observation. Histological analysis of sonication treated-samples by van Gieson staining demonstrated complete nuclei removal compared to the control samples. The Picrosirius red and Safranin-O/Fast green staining indicate the preservation of collagen and glycosaminoglycans (GAGs) structure, respectively. In addition, the morphological observation by SEM shows the availability of micropores on the surface of decellularized sample. Consequently, the sonication decellularization treatment did not affect extracellular matrix (ECM) properties, while forming micropores on the surface of meniscus tissues. This made it possible to proceed in other fulfillment of bioscaffold preparation

Histological and biochemical evaluations of decellularized meniscus tissues using sonication treatment system

Meniscus plays fundamental roles in the knee mechanisms and functions but injuries happen in meniscus have poor healing ability that requires great interventions. Tissue engineered scaffolds serve as one of the interventions to regenerate the required tissue to treat early degenerative joint disease. The purpose of this research is to examine the effectiveness of sonication treatment system in complete cellular components removal with preserved extracellular matrix (ECM) compositions in meniscus tissues through histological and biochemical evaluations. Meniscus tissues were decellularized using sonication treatment system for 10 hours treatment time and continued with extensive washing process. Histological evaluations were based on van Gieson and Picrosirius red staining that portrayed complete cellular components removal and preserved collagen networks distribution within sonicated scaffolds respectively. Biochemical evaluations showed markedly reduction in the residual DNA content for sonicated scaffolds while maintain in collagen content. Lastly, agarose gel electrophoresis showed no visible DNA bands for sonicated scaffolds. Therefore, the results concluded that the prepared bioscaffolds by sonication treatment system managed to reduce the immunogenicity of scaffolds by removing most of the cellular components and successfully retained the properties of the extracellular matrix. Thus, it is a suitable decellularization method to be used in tissue engineering applications

新規循環ソニケーション技術により調製した脱細胞化マトリックスの動脈組織再生への適用

学位の種別: 論文博士審査委員会委員 : (主査)東京大学教授 光嶋 勲, 東京大学准教授 百瀬 敏光, 東京大学准教授 星 和人, 東京大学准教授 阿部 裕輔, 東京大学准教授 伊藤 大知University of Tokyo(東京大学