Heterogeneous pattern of gene expression in cloned cell lines established from a rat transplantable osteosarcoma lung metastatic nodule

We have established three cloned cell lines (COS1NR, COS2NR and COS4NR) from the lung metastatic nodule of a highly metastatic variant of rat transplantable osteosarcoma, C-SLM. All three clones shared the same morphological characteristics and tumorigenicity, but their growth rates in vitro and metastatic ability in vivo differed from each other. Single-strand conformation polymorphism (SSCP) analysis revealed all three clones to have the same p53 gene mutation and parent C-SLM tumor. On the other hand, Northern blot analysis showed a different pattern of expression for the genes, c-fos, c-jun, c-Ha-ras, transin (rat stromelysin), bone Gla protein (osteocalsin) and nm23/NDP kinase. These results indicate the presence of a heterogeneous cell population in terms of the different pattern of gene expression in a lung metastatic nodule of rat osteosarcoma and the present newly established cell lines will be useful for further investigation of the biological behavior of osteosarcomas.     

Surgical treatment of Cronkhite-Canada syndrome associated with protein-losing enteropathy: report of a case

PURPOSE: The case of a patient with Cronkhite-Canada syndrome, who developed a protein-losing enteropathy, is reported. METHODS: After localization of the protein-losing region, a right colectomy was performed. RESULTS: Hypoproteinemia and ectodermal changes improved postoperatively. CONCLUSIONS: Surgery is an effective treatment for protein-losing enteropathy in Cronkhite-Canada syndrome. Ectodermal changes improve after correcting malnutrition.     

A mammalian genetic system to screen for small molecules capable of disrupting protein-protein interactions

A mammalian two-hybrid system was developed for high-throughput screening of compounds that disrupt specific protein-protein interactions. The existing mammalian systems are unsatisfactory for drug screening due to nonregulated expression of interacting proteins. To construct a tightly regulated system, the tetracycline repressor was fused with the inhibitory KRAB domain as a suppressor. The binding of the suppressor to the tet operator entirely blocked expression of two interacting proteins. When both the inducer doxycycline and drugs were added to the culture, the reporter gene was either activated by interaction of the paired proteins with ineffective drugs or remained silent due to disruption of the protein interactions by the effective drugs. We demonstrate that interactions of the type I receptor for TGFbeta with FKBP12 and the epidermal growth factor receptor (EGFR) with p85 are effectively disrupted by FK506 and EGFR kinase inhibitor AG1478, respectively. The power of this system for drug screening was further demonstrated by rapid identification of inhibitors from a druglike library for the receptor kinases.     

Vortex behavior in Nb3Ge microbridges

We have fabricated Nb₃Ge microbridges, including those with variablethickness geometry, with submicrometer lengths, by means of plasma etching combined with lithographic techniques. The measuredI-V characteristic and the temperature variation of the critical current are consistent with that expected from the vortex concept. However, a deviation is observed in the microwave steps: the magnitude of the critical current oscillates with microwave power in a manner which agrees with an analog simulation based on the RSJ model. We have found a strong correlation between the bridge behavior and the film parametersT _c and ρ _n (normal resistivity). The critical current is reduced rapidly with a decrease inT _c and an increase in ρ _n , while in high-T _c and low-ρ _n bridges a linearI-V characteristic appears at low voltages. Taking into account the influence of pinning, we discuss the results in terms of vortex motion.     

Analysis of protein adsorption and binding at biosensor polymer interfaces using X-ray photon spectroscopy and scanning electrochemical microscopy

We describe a method, based on X-ray photoelectron spectroscopy (XPS) measurements, to assess the extent of protein adsorption or binding on a variety of different muTAS and biosensor interfaces. Underpinning this method is the labeling of protein molecules with either iodine- or bromine-containing motifs by using protocols previously developed for radiotracer studies. Using this method, we have examined the adsorption and binding properties of a variety of modified electrodeposited polymer interfaces as well as other materials used in muTAS device fabrication. Using polymer interfaces modified with poly(propylene glycol) (PPG) chains, our results indicate that a chain of at least approximately 30 monomer units is required to inhibit nonspecific adsorption from concentrated protein solutions. The XPS methodology was also used to probe specific binding of avidins and enzyme conjugates thereof to biotinylated and mixed biotin/PPG-modified polymer interfaces. In one example, using competitive binding, it was established that the mode of binding of a peroxidase-streptavidin conjugate to a biotinylated modified polymer interface was primarily via the streptavidin moiety (as opposed to nonspecific binding via the enzyme conjugate). XPS evaluation of nonspecific and specific peroxidase-streptavidin immobilization on various functionalized polymers has guided the design and fabrication of functionalized interdigitated electrodes in a biosensing muTAS device. Subsequent characterization of this device using scanning electrochemical microscopy (SECM) corroborated the adsorption and binding previously inferred from XPS measurements on macroscale electrodes.     

Extraction rice-planted areas by RADARSAT data using neural networks

A classification technique using the neural networks has recently been developed. We apply a neural network of learning vector quantization (LVQ) to classify remote-sensing data, including microwave and optical sensors, for the estimation of a rice-planted area. The method has the capability of nonlinear discrimination, and the classification function is determined by learning. The satellite data were observed before and after planting rice in 1999. Three sets of RADARSAT and one set of SPOT/HRV data were used in Higashi–Hiroshima, Japan. Three RADARSAT images from April to June were used for this study. The LVQ classification was applied the RADARSAT and SPOT to evaluate the estimate of the area of planted-rice. The results show that the true production rate of the rice-planted area estimation of RADASAT by LVQ was approximately 60% compared with that of SPOT by LVQ. It is shown that the present method is much better than the SAR image classification by the maximum likelihood method.     

A distributed routing method for AGVs under motion delay disturbance

In real transportation environments for semi-conductor manufacturing, unexpected disturbances such as motion delays and/or sudden requests for transportation may cause collisions among AGVs increasing total transportation time. It is required to generate a collision-free routing for multiple automated guided vehicles (AGVs) within a few seconds. In this paper, we propose a distributed routing method under motion delay disturbance for multiple AGVs. The proposed method features a characteristic that each AGV subsystem derives its optimal route to minimize the sum of the transportation time and the penalties with respect to collision probability with other AGVs. The penalties reflect the collision probability distribution function for motion delay disturbances. The proposed method is applied to a routing problem for transportation in the semiconductor fabrication bay with 143 nodes and 20 AGVs. The computational results show that the total transportation time obtained by the proposed method is shorter than that of the conventional method. For dynamic transportation environments, an optimal timing for re-routing multiple AGVs under motion delay disturbance is systematically determined by the tradeoff relationship between the total computation time to derive a solution and the uncertainties for re-routings. Markov chain is used to represent uncertainty distribution for re-routings. The proposed method is implemented in an experimental transportation system with 51 nodes and 5 AGVs. The experimental results demonstrate that the proposed method is applicable to real transportation environments.     

Discharge characteristics and low‐voltage driving of high‐Xe‐content PDPs

Abstract— High‐Xe‐content PDPs attain improved luminous efficiency, but with sacrifices of higher sustain and address voltages and slower discharge build‐up. By examining PDPs with 3.5–100% Xe contents, it was revealed that space‐charge priming as well as wall‐charge accumulation are effective in obtaining low‐voltage and high‐speed operation. In addition, it was found that the effectiveness is emphasized for higher‐Xe‐pressure PDPs. In this respect, erase addressing is more favorable than write addressing, especially for high‐Xe‐pressure PDPs. The formative time lag of the discharge and diffusion/drift of the space charges are shorter for high Xe contents. In this respect, high‐Xe‐content PDPs have a potential for high‐speed addressing, if driven adequately. The use of space‐charge priming, however, is limited by the duration between the priming and scan pulses. Accumulation of wall charges is limited by ignition of a self‐erase discharge with which all the wall charges are dissipated. Although the highest efficiency and luminance are attained with a 100%‐Xe panel, the optimum Xe gas content, considering the sustain pulse voltage and drive voltage margin, would be 70% Xe + Ne.     

State difference feedback for stabilizing uncertain steady states of non-linear systems

Supposing a non-linear system is subjected to parametric uncertainties, the present paper aims at stabilizing its unstable steady states. A distinctive feature of the problem is that exact information about the steady state is unavailable. To cope with the difficulty, we have examined the applicability of the state difference feedback which uses the difference between the present state x(t) and the past state x(t-T). A rigorous stability analysis has been executed for the case where state deviations are controllable by a single input variable. The stability analysis has led to a favourable conclusion that if the number of unstable modes is just two, and if they are not associated with the origin in the complex plane, we are always able to find a controller which stabilizes the deviations from the unknown steady state. Design process is illustrated by using two kinds of pendulum systems.