Formation of thrombi is a complex biological event involving platelets and coagulation cascades. The both have been well investigated individually. However, the inter-relationship between them is still to be elucidated. The recent progresses in computer technology may allow us to simulate complex biological phenomena in silico. Here we report a novel method to reproduce the complex system of the inter-relationship between platelet and coagulation by combining the previous simulation model of platelet adhesion with the model of coagulation cascade. We have reproduced the biological process of thrombus growth occurring in the mice cremasteric artery induced by endothelial injury by FeCl₃ with our newly developed computer simulator.

In this experiment, large amplitude oscillatory shear, differential strain and pre-stress measurements were performed on sample solutions of mixed kappa carrageenan and iota carrageenan solutions. As measurements enter the nonlinear regime, properties of soft materials and complex fluids yield a wide array of responses due to flow instabilities or network structure. LAOS experiments reveal that mixed carrageenan solutions exhibit intermediate properties of the kappa and iota components. At large enough strains, all gels exhibit strain softening in the elastic moduli due to irreversible deformations introduced in the gel networks. However, there is an expressed increase in the viscous moduli of both iota and the mixed gel until both transitions from a predominantly elastic to a viscous material. The softening of the elastic moduli and expressed increase in the viscous moduli is a hallmark behavior of soft glassy materials.

Visualisation is a simple approach to scientific investigation, which has been used extensively since the microscope was invented in the early 17th century. The in-vivo observation of renal circulation by light microscopy was first performed in the late 20th century. Light microscopy enables measurement of only two dimensions in an image, unless sequential analysis is performed. For a more comprehensive and accurate quantitative study of renal function, a novel modality is required. Since the late 20th century, confocal laser microscopy has been applied in the study of organ function. This technology enabled deep sectioning of living tissue, with the use of fluorescence techniques. It has added a new dimension to visualisation studies in renal physiology, both in-vitro and in-vivo. Here, through the compilation of several representative studies, we briefly review the major advances in in-vivo visualisation of renal physiology. With the ability to analyse differences in the emission intensity and distribution of fluorescent probes with sequential measurements, more quantitative in-vivo studies are expected to follow.

We have elucidated the heat induced formation of wormlike micelles in the mixture solutions containing two different geometric amphiphiles of lysophosphatidylcholine (LPC) and phosphatidylcholine (PC), where LPC and PC have one and two alkyl chains as hydrophobic groups, respectively. The mixture solutions showed the increases in viscosity and transparency by heating, and showed the highest viscosity at the ratio of LPC/PC = 1.67, suggesting the formation of long wormlike micelles attained by the average cpp around 0.5 favorable. From the dynamic rheological measurements, it was found that the elasticity was proportional to the square of total concentration of LPC and PC, indicating the existence of entanglement among long wormlike micelles. Other mixture solutions seem to be mixtures of spherical, lamellar and wormlike micelles with different sizes judging from the viscoelastic behavior and transparency, where the sizes changed reversibly with the temperature changes.

BACKGROUND: High shear stress (SS) could affect vascular remodeling during initiation of cerebral aneurysms. However, the response of smooth muscle cells (SMCs) to high SS, which is related to blood vessel remodeling, are poorly understood. OBJECTIVE: We explored the effect of high SS on SMCs in an EC-SMC co-culture model to investigate blood vessel remodeling during aneurysm formation. METHODS: SMCs were three-dimensionally cultured in a collagen gel, with ECs cultured on a membrane filter above the SMCs. Then, the co-culture model was exposed to different SS of 0.2, 2, 6, and 10 Pa for 72 h. RESULTS: A physiological SS of 2 Pa maintained the expression of contractile proteins in SMCs, whereas lower or higher SS decreased the expression, suggesting a phenotypic change to a synthetic state. Furthermore, we found that a high SS of 10 Pa increased production of both matrix metalloproteinase (MMP) -2 and -9 from SMCs, which could induce destructive blood vessel remolding. CONCLUSIONS: High SS could change the SMC phenotype to a synthetic state and induce higher MMP production by SMCs in the co-culture model. These results may help to further elucidate blood vessel remodeling mechanisms under high SS conditions.

Erythrocyte deformability plays a key role in pulmonary microcirculation, which raised the hypothesis that erythrocyte deformability is impaired in pulmonary thromboembolism (PTE) and subsequent chronic thromboembolic pulmonary hypertension (CTEPH). We encountered a case of PTE followed by CTEPH and investigated erythrocyte deformability by our specified filtration technique to test this hypothesis. Erythrocyte deformability was normal before but was impaired after the onset of PTE. It was restored partially in the stage of CTEPH. This case taught us that erythrocyte deformability is impaired and that this impairment relates to the hemodynamics of pulmonary microcirculation and pathophysiology of PTE and CTEPH.