Integrin signaling: cytoskeletal complexes, MAP kinase activation, and regulation of gene expression

Members of the integrin family of adhesion receptors mediate interactions of cells with the extracellular matrix. Besides their role in tissue morphogenesis by anchorage of cells to basement membranes and migration along extracellular matrix proteins, integrins are thought to play a key role in mediating the control of gene expression by the extracellular matrix. Studies over the past 10 years have shown that integrin-mediated cell adhesion can trigger signal transduction cascades involving translocation of proteins and protein tyrosine phosphorylation events. In this review, we discuss approaches used in our lab to study early events in integrin signalling as well as further downstream changes.     

Integration of artificial market simulation and text mining for market analysis

This paper proposed a new approach that integrated an artificial market simulation and text-mining. In this approach first economic trends were extracted from text data circulating in the real world. Then, the trends were inputted into the market simulation. The simulation could support users’ action to the actual market. This approach was used for the decision of exchange rate policy and suggested that the combination of interest rate and intervention operation was effective for the stabilization of the yen–dollar rate from 1994 to 1995. This approach can offer a useful social simulation as a tool to users.     

Role of transforming growth factor-beta1 in the pathogenesis of moyamoya disease

N-Nitroso propoxur (NP) can be synthesized from a widely used N-methylcarbamate insecticide, propoxur, in vitro in the laboratory. Because of the extensive use of aerosol propoxur, the adverse effect on cells of respiratory origin is worth elucidating. In this report, two mammalian cell cultures from respiratory tissues [a hamster lung fibroblast, V79, and a primary rat tracheal epithelial cell (RTE)], were used to investigate the genotoxicity of propoxur and NP. NP was more cytotoxic than propoxur, with LC50s (20 and six times smaller, respectively in V79 and RTE cells. NP significantly induced sister chromatid exchange (> or = 0.01 microg/ml), chromosome aberration (> or = 2.5 microg/ml) and hprt gene mutation (> or = 0.5 microg/ml) in V79 cells, and cell transformation (> or = 0.2 microg/ml) in RTE cells. Results of chromosome aberration and hprt gene mutation indicated that the major pre-mutagenic lesion induced by NP must be the O6-methylguanine adduct, which frequently mispairs with thymine and thus gives rise to a GC-->AT transition. Propoxur was not mutagenic to either type of cells. However, it inhibited gap-junctional intercellular communication in V79 cells, which indicates that propoxur could act through some epigenetic mechanisms, such as tumor promotion or cell proliferation, in the multiple process of chemical carcinogenesis.     

Radiotherapy in the treatment of brain metastasis from small cell lung carcinoma: study on appropriately controlled dose

Fifty-two brain metastatic lesions occurring in 20 patients with small cell lung carcinoma (SCLC) were irradiated, and then the relationship between tumor size, dose and control was clinically and histopathologically studied. Lesions of 8 mm in diameter and those of 10 mm in diameter were determined to be controllable by irradiation at about 38 Gy and 42 Gy, respectively. According to size-dependent curative minimum doses, the lesions could be divided by the 10 Gy/ 5fr/wk method into controlled and non-controlled groups with the curve expressed as dose (Gy) = 15.27 log10 [tumor volume (mm3)] +0.6. Based on these results, tumors of 2 mm and 3 mm in diameter were estimated to be controllable at 14 and 20 Gy, respectively. Thus prophylactic cranial irradiation (PCI) in the treatment of SCLC was thought to be not always necessary if early treatment of small metastatic lesions, detected by Gd-DTPA-enhanced MRI could be achieved. The optimal interval between follow-up examinations was thought to be 1 month during the first two years after the diagnosis of SCLC, and then 3 months after that. In addition, the omission of PCI can save many patients who do not actually require PCI from suffering its adverse effects.     

Rudimentary meningocele of the scalp

A rudimentary meningocele, a variant of primary cutaneous meningioma, was seen on the scalp of a 9-month-old Japanese boy. Clinically, the lesion on the left parietal area was round, about 1.6 cm in diameter, alopecic, and slightly elevated. Histologically, the lesion, located from the dermis to the subcutis, consisted of scattered foci of meningothelial cells, an anastomosing network of empty spaces with psammoma bodies and collagen bodies, and small vessels. Immunohistochemically, the meningothelial cells were positive for vimentin and desmin. Ultrastructurally, they had elongated cytoplasmic processes, intermediate filaments in the cytoplasm, and desmosomal junctions.     

Acquisition of ground penetrating radar data to detect lava tubes: preliminary results on the Komoriana cave at Fuji volcano in Japan

Ground penetrating radar (GPR) has been successfully used to detect a lava tube in a basaltic lava flow from the Fuji volcano, Japan. The target lava tube, Komoriana cave, is in the northern part of the Aokigahara lava flow which was emplaced over 1,000 years ago. The lava tube was detected by simply dragging the GPR antenna along a prefecture road, demonstrating the advantages of this method compared with detailed mapping and geological investigations. As a massive basaltic lava flow allows deep penetration of the radar pulse, the reflection radar profile obtained showed two very clear structures which were interpreted from the waveforms to be the roof and the bottom of the lava tube from the waveforms alone. This was subsequently confirmed by careful survey measurements of the Komoriana cave lava tube. The feasibility study clearly demonstrated that GPR is a very effective and convenient tool for discovering unknown lava tubes hidden deeply inside lava flows.     

Semiconducting Layer impedance and its effect on cable wave-propagation and transient Characteristics

This paper has derived an impedance formula for conductor's semiconducting layer based on a conventional circuit theory. The formula is confirmed to be identical to an accurate one derived by solving Maxwell's equation. A wave-propagation characteristic and a transient voltage on a cable having the semiconducting layer on the conductor's surface are evaluated by applying the derived formula, and are compared with those on a cable with no semiconducting layer. The semiconducting layer increases the conductor impedance, and thus, the attenuation constant is increased, and the propagation velocity and the characteristic impedance are decreased for a coaxial mode by the semiconducting layer, but the inter-phase mode of propagation is not affected. A transient voltage is attenuated more and its oscillating period becomes greater than those on a cable with no semiconducting layer. The effect of the semiconducting layer impedance on the wave-propagation characteristic and the transient voltage is rather minor when the layer thickness is small and the resistivity is high, and the semiconducting layer effect is dominated by its admittance.