Establishment and characterization of a new erythropoietin-dependent acute myeloid leukemia cell line, AS-E2

We have established an erythropoietin-dependent human leukemia cell line, AS-E2, from a patient with acute myeloid leukemia. These cells have many characteristics of late erythroid progenitor cells, they are positive for CD36, Glycophorin A, and CD71 but negative for CD41, and positive for benzidine and PAS staining. These cells express GATA-1 and have low affinity erythropoietin (EPO) receptor on their surface. Interestingly, AS-E2 cells are strictly dependent on EPO for their growth and survival; other cytokines including GM-CSF, stem cell factor, or IL-3 cannot support the growth of this cell line. These features are similar to late erythroid lineage cells, like normal BFU-E or CFU-E, and we have demonstrated that EPO stimulation induces the tyrosine phosphorylation of several proteins in AS-E2 cells including the EPO receptor and JAK2 kinase. This new cell line is a useful reagent to study biological and molecular events during the late stages of erythropoiesis, and to understand transforming events in human erythroid cells.     

Monoclonal antibodies against pig ovarian follicular granulosa cells induce apoptotic cell death in cultured granulosa cells

Two monoclonal antibodies capable of inducing granulosa cell apoptosis were produced against granulosa cells prepared from antral follicles of pig ovaries. The healthy follicles, 4-5 mm in diameter, were dissected from the ovaries of gilts, and then granulosa cells were isolated. BALB/c female mice were immunized with the isolated granulosa cells. Antibodies against the granulosa cells were detected by immunofluorescent staining using frozen ovarian sections. The isolated spleen cells prepared from immunized mice producing antibodies against the granulosa cells were fused with Sp2/O-Ag 14 mouse myeloma cells by standard hybridization techniques. Two hybridoma clones, PFG-1 and PFG-2, which produced specific IgM antibodies against granulosa cells were selected. Western blotting analysis revealed that PFG-1 and PFG-2 antibodies specifically recognized cell-membrane proteins with molecular weights of 55 and 70 kD and isoelectric points of 5.9 and 5.4, respectively. The monoclonal antibodies immunohistochemically reacted with granulosa cells of healthy follicles. When the isolated granulosa cells prepared from healthy follicles were cultured in medium containing 0.1 or 10 micrograms/m/PFG-1 or PFG-2 antibodies, respectively, the cells underwent apoptosis as determined by nuclear morphology, DNA electrophoresis and flow cytometric analysis. In conclusion, these two monoclonal antibodies against granulosa cells have cell-killing activity in cultured granulosa cells.     

Evaluation of robust control by universal learning networks

The characteristics of control system design using a universal learning network (ULN) are such that both the controlled systems and their controller are represented in a unified framework, and that the learning stage of the ULN can be executed by using not only first-order derivatives (gradient) but also the higher order derivatives of the criterion function with respect to parameters. ULNs have the same generalization ability as neural networks. So the ULN controller is able to control the system in a favorable way under an environment which is little different from the environment of the control system at the learning stage. However, stability cannot be sufficiently realized. In this paper, we propose a robust control method using a ULN and second-order derivatives of that ULN. Robust control, as considered here, is defined as follows. Even though the initial values of the node outputs are very different from those at the learning stage, the control system is able to reduce its influence to other node outputs and can control the system as in the case of no variation. In order to realize such robust control, a new term concerning the variation is added to the usual criterion function, and the parameters are adjusted so as to minimize the above-mentioned criterion function using second-order derivatives of the criterion function with respect to the parameters. Finally, it is shown that the ULN controller constructed by the proposed method works effectively in a simulation study of a non-linear crane system. This work was presented, in part, at the International Symposium on Artificial Life and Robotics, Oita, Japan, February 18–20, 1996     

Increased sensitivity of gastric cancer cells to natural killer and lymphokine-activated killer cells by antisense suppression of N-acetylgalactosaminyltransferase

UDP-N-acetylgalactosamine:polypeptide N-acetylgalactosaminyltransferases (GalNAc transferases) catalyze the initial reaction in O-linked (mucin type) oligosaccharide biosynthesis. To attempt to inhibit the synthesis of O-glycan, we transfected antisense cDNA of GalNAc transferase type 1 (GalNAc-T1) into a human gastric cancer cell line, JRST. A decreased expression of GalNAc-T1 at the level of both mRNA and protein was observed in the resultant transfectants. They demonstrated a significantly increased sensitivity to NK and lymphokine-activated killer cells in vitro compared with parental cells and mock transfectants. Although there was no significant difference in in vitro cell proliferation among parental cells, mock transfectants, or antisense transfectants, the in vivo growth rate of antisense transfectants using SCID mice was clearly lower than that of parental cells and mock transfectants. Furthermore, the treatment of mice with anti-asialo-G(M1) Ab abolished this growth-inhibitory effect of antisense transfection. From these results, we conclude that antisense suppression of GalNAc-T1 could increase the sensitivity of tumor cells to NK and lymphokine-activated killer cells, suggesting that this strategy may be of use as a new immunogene therapy.     

Mmic technology for communication systems

MMIC technology is recently progressing at a rapid rate and is now being applied in communications systems. However, there remain few practical applications. This is mainly due to the high cost of conventional mmics because of the small market size and specialized needs. This paper introduces three new technical approaches that overcome the problems: uniplanar mmic, line unified fet^lufet), and multilayer mmic. Concepts and several examples of these technologies are described. It is shown that these technologies are effective not only for cost reduction but also for increased performance. In addition, one example of system application is described.     

99Tcm-MAG3: a sensitive indicator for evaluating perfusion and rejection of renal transplants

Radionuclide renography has a role in evaluating perfusion of transplanted kidneys. In the course of rejection, cortical perfusion decreases before urinary excretion changes. Based on the facts that 99Tcm-MAG3 has different pharmacokinetics and shows a higher kidney-to-background count ratio than 99Tcm-DTPA, we postulated that 99Tcm-MAG3 was a sensitive and reproducible agent to measure cortical perfusion of transplanted kidneys. To clarify the feasibility of using 99Tcm-MAG3 to measure the cortical perfusion index (CPI), sequential renography was performed using 99Tcm-DTPA and 99Tcm-MAG3 in 14 patients with stable renal transplants, who had changes in serum creatinine concentration of less than 50% between the two studies. The CPI was calculated with 99Tcm-DTPA and 99Tcm-MAG3 and these were then compared and correlated with concurrent serum creatinine concentration. The CPI with 99Tcm-MAG3 was 1.43 times that with 99Tcm-DTPA in patients with changes in serum creatinine concentration equal to or less than 20%, and regression analysis revealed that the difference in CPI was larger in patients with more severely decreased renal perfusion than in patients with normal or mildly decreased renal perfusion. This preliminary study has indicated that the CPI with 99Tcm-MAG3 is a sensitive index for detecting changes in renal function, and thus is a feasible indicator of cortical perfusion when evaluating the rejection of transplanted kidneys.     

Idiopathic restrictive cardiomyopathy with diffuse perimyocytic fibrosis--a rare observation

Idiopathic restrictive cardiomyopathy (RCM) is rare. Even today little is understood of its etiology or underlying mechanisms, and definitive diagnostic criteria are lacking. In this report, we describe a case of idiopathic RCM in a young Japanese woman who died while awaiting cardiac transplantation during the 5-year course of the disease. Rare pathologic findings of diffuse perimyocytic fibrosis were revealed at autopsy.     

Phorbol ester stimulates PAF synthesisvia the activation of protein kinase C in rat leukocytes

When rat pleural mononuclear leukocytes were stimulated with 1 μM phorbol myristate acetate (PMA), platelet-activating factor (PAF)-like activity was detected in the supernatant and the cellular fractions of the incubation mixture, as measured by rabbit platelet aggregation. C₁₆PAF activity peaked at 30 min in both fractions. Acetyltransferase activity in the microsomal fraction of the stimulated cells also increased rapidly and showed a peak at 10 min. A protein kinase C inhibitor, staurosporine, and an inhibitor of phospholipase A₂,p-bromophenacylbromide, inhibited stimulated PAF formation in both fractions. Staurosporine also inhibited PMA induced acetyltransferase activity. The data suggest that PMA stimulates PAF synthesis by the remodeling pathway in rat pleural cells through activation of both phospholipase A₂ and acetyltransferase, and that the acetyltransferase, in turn, may be activated through activation of protein kinase C. Based on a paper presented at the Third International Conference on Platelet-Activating Factor and Structurally Related Alkyl Ether Lipids, Tokyo, Japan, May 1989.     

A 2-V, 1-10 GHz BiCMOS transceiver chip for multimode wirelesscommunications networks

This paper concerns the design consideration, fabrication process, and performance results for an ultra-broadband, low-voltage, low-power, BiCMOS-based transceiver chip for cellular-satellite-LAN wireless communication networks. The transceiver chip incorporates an RF amplifier, a Gilbert down-mixer, and an IF amplifier in the receive path, and an IF amplifier, a Gilbert up-mixer, and an RF amplifier in the transmit path. For an RF frequency in the 1-10 GHz band and an IF frequency in the 100-1000 MHz band, the developed transceiver chip consumes less than 60 mW at 2 V, to yield a downconversion gain of 40 dB at 1 GHz and 10 dB at 10 GHz and an upconversion gain of 42 dB at 1 GHz and 11 dB at 10 GHz. To avoid possible start-up problems caused during “stand-by” to “enable” mode transition, a simple switching technique is employed for enabling either the receive or the transmit path, by changing the value of a reference voltage applied to both the down- and the up-mixers. While the developed transceiver chip exhibits the best performance for a dc supply voltage of 2 V, it shows a graceful degradation for a ±0.15 V voltage deviation. The transceiver's chip size is 1.04 mm×1.04 mm     

Multilateral analysis of increasing collective dose and new ALARA programme

JAPC (The Japan Atomic Power Company) is the only electric power company that operates different types of nuclear reactors in Japan; it operates two BWRs (boiling water reactors), one pressurised water reactor and one gas cooled reactor. JAPC has been conducting various activities aimed at reducing radiation dose received by workers for over 45 y. Recently, the collective dose resulting from periodic maintenance has increased at each plant because of the replacement of large equipment and the unexpected extension of the outage period. In particular, the collective dose at Tokai-2 is one of the highest among Japanese BWR plants((1)), owing to the replacement and strengthening of equipment to meet earthquake-proof requirements. In this study, the authors performed a multilateral analysis of unacceptably a large collective dose and devised a new ALARA programme that includes a 3D dose prediction map and the development of machines to assist workers.