16S rRNA gene sequence of Rubrobacter radiotolerans and its phylogenetic alignment with members of the genus Arthrobacter, gram-positive bacteria, and members of the family Deinococcaceae

The nearly complete sequence of the 16S rRNA gene of an extremely highly radiotolerant bacterium, Rubrobacter radiotolerans (reclassified from Arthrobacter radiotolerans based on chemical characteristics), was determined by PCR amplification of the genomic DNA followed by cloning of the amplified gene and sequencing by the dideoxynucleotide method. The sequence was aligned with the sequences of members of the genus Arthrobacter and also with the sequences of representatives of the gram-positive bacteria having high G + C contents and the family Deinococcaceae (radioresistant micrococci and their relatives). The results of our phylogenetic analysis confirmed that R. radiotolerans is not a member of the Arthrobacter group and thus supported the previous reclassification. Moreover, although it is radioresistant and has a high G+C content, R. radiotolerans is more closely related to the gram-positive bacteria with high G+C contents than to the radioresistant members of the Deinococcaceae.     

Methylmercury decreases IL-1beta immunoreactivity in the nervous system of the developing frog Xenopus laevis

In aquatic ecosystems, mercury can become methylated and act as a potent environmental toxin, producing developmental and neurotoxic effects in a variety of species, including frogs. Molecular indicators provide a means of assessing exposure to methylmercury and for understanding how it and other environmental toxins alter cellular function. Molecules such as growth or survival factors, and cytokines are good candidates for molecular indicators of exposure and/or damage because they are intimately related to cell and molecular processes that underlie normal growth and function. The cytokine, IL-1beta, was measured in whole frog embryos using Western blot methods and in specific structures using immunocytochemistry after exposure to 0, 10, 25, 50 and 100 parts per billion (ppb) methylmercury chloride (mmc). We observed no significant changes in total IL-1beta in whole embryo extracts. However, statistically significant decreases in IL-1beta were observed in the Vth cranial ganglion and myotomal blocks of Xenopus laevis embryos exposed to concentrations greater than or equal to 50 ppb mmc. In addition, increased mortality and alterations in gross morphology and behavior were altered by these same concentrations of mmc. Thus, frog embryos are highly susceptible to low levels of mmc contamination, and IL-1beta is an indicator of mmc exposure in the nervous system.     

Basic examination concerning multiagent cooperation with entrainment

The study of a multiagent system generating a new function was carried out. A coordinate solution, such as the multiagent system, is effective for complicated problems. Therefore, it is necessary for agents to behave systematically while building cooperative relations with each other. We pay attention to an entrainment phenomenon which can be seen in life phenomena, such as cardiac muscle cells or the emission of light by a firefly, as an element to promote organized behavior between agents. We suggest a new system model unlike conventional systems.     

Frontier of transparent oxide semiconductors

Recent advancements of transparent oxide semiconductors (TOS) toward new frontiers of “oxide electronics” are reviewed based on our efforts, categorized as “novel functional materials”, “heteroepitaxial growth techniques”, and “device fabrications”. Topics focused in this paper are: (1) highly conductive ITO thin film with atomically flat surface, (2) p-type TOS material ZnRh₂O₄, (3) deep-ultraviolet (DUV) transparent conductive oxide β-Ga₂O₃ thin film, (4) electrochromic oxyfuolide NbO₂F, (5) single-crystalline films of InGaO₃(ZnO)_m grown by reactive solid-phase epitaxy, (6) p-type semiconductor LaCuOS/Se epitaxial films capable of emitting UV- and purple-light, (7) p–n homojunction based on bipolar CuInO₂, (8) transparent FET based on single-crystalline InGaO₃(ZnO)₅ films, and (9) UV-light emitting diode based on p–n heterojunction.     

Nedd5, a mammalian septin, is a novel cytoskeletal component interacting with actin-based structures

The mouse Nedd5 gene encodes a 41.5-kD GTPase similar to the Saccharomyces and Drosophila septins essential for cytokinesis. Nedd5 accumulates near the contractile ring from anaphase through telophase, and finally condenses into the midbody. Microinjection of anti-Nedd5 antibody interferes with cytokinesis, giving rise to binucleated cells. In interphase and postmitotic cells, Nedd5 localizes to fibrous or granular structures depending on the growth state of the cell. The Nedd5-containing fibers are disrupted by microinjection of GTPgammaS and by Nedd5 mutants lacking GTP-binding activity, implying that GTP hydrolysis is required for its assembly. The Nedd5-containing fibers also appear to physically contact actin bundles and focal adhesion complexes and are disrupted by cytochalasin D, C3 exoenzyme, and serum starvation, suggesting a functional interaction with the actin-based cytoskeletal systems in interphase cells.     

The role of transforming growth factor-beta in PEG-rHuMGDF-induced reversible myelofibrosis in rats

Pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF) injected at a suprapharmacologic dose (100 microg/kg) daily for 5 d in normal rats caused marked increases in marrow megakaryocytes and platelet counts at 6-8 d followed by gradual decreases to control levels at 10-20 d. Interestingly, in addition to the expected thrombopoiesis, PEG-rHuMGDF was associated with myelofibrosis with a predominance of reticulin fibres at day 10 followed by complete normalization by day 20. At 6-8 d, the levels of transforming growth factor-beta1 (TGF-beta1) in the extracellular fluid of the marrow, the platelet poor plasma, and the platelet extract were increased 23-, 7- and 2-fold, respectively. The elevated levels of TGF-beta1 were gradually reduced to baseline levels at 13-20 d in accordance with the normalization of myelofibrosis and thrombopoiesis. An ultrastructural analysis showed that large fragments of megakaryocytes were deposited in the marrow parenchyma of PEG-rHuMGDF-treated rats at day 6. PEG-rHuMGDF administration at pharmacologic doses (1 and 10 microg/kg) did not induce the deposition of reticulin fibres in the marrow. These findings suggest that TGF-beta1 leaked from megakaryocytes is involved in the development of the PEG-rHuMGDF-induced myelofibrosis and that this is a reversible process related to the regulation of the excess production of platelets.     

The incidence of hepatocellular carcinoma in patients with chronic hepatitis C after interferon treatment

To determine whether serum hepatitis C virus (HCV) RNA disappearance after interferon (IFN) treatment prevents development of hepatocellular carcinoma (HCC), we evaluated retrospectively the incidence of HCC in patients with chronic hepatitis C. A total of 213 patients were monitored for more than 6 months after completion of IFN treatment. Sixty-three of the 213 patients (29.6%) achieved a complete response (CR) to treatment and 150 (70.4%) had no response (NR). HCC developed in 12 (5.6%), all of whom were NR. Logistic analysis showed age, alpha -fetoprotein, and staging of histological finding before IFN treatment were independent factors to development of HCC. The fact that there was no HCC development from CR provides a basis for IFN treatment in chronic HCV infection.     

Device applications of transparent oxide semiconductors: Excitonic blue LED and transparent flexible TFT

Recent progress in oxide-based transparent optoelectronic devices is reviewed. It is important to understand electronic structures inherent to oxides in order to develop new materials and to find suitable device applications that oxide materials can have distinct advantages over conventional semiconductors. Two new transparent oxide semiconductors, (i) p-type layered oxychalcogenides LaCuOCh (Ch = chalcogen), and (ii) large-mobility amorphous oxide semiconductors (AOSs), are taken as examples. Their peculiar properties are discussed in comparison with conventional semiconductors based on consideration of electronic structures. Two associated devices, an excitonic light-emitting diode using LaCuOCh and transparent flexible thin film transistors using AOSs, are also shown.     

Evans'' syndrome associated with Graves'' disease

A 36-year-old woman who had had Graves' disease for 6 years was admitted with severe thrombocytopenia. Evans' syndrome was diagnosed. The patient's family history showed multiple cases of Graves' disease but no cases of Evans' syndrome. Both conditions in this patient improved with corticosteroid and thiamazole therapy. Several autoimmune antibodies were found, but a common autoimmune mechanism was not clearly shown. Although the combination of Graves' disease and Evans' syndrome had not occurred previously in her family, genetic factors may play an important role in the pathogenesis of both conditions.     

Performance analysis of fast reservation protocols in ATM networks

In Asynchronous Transfer Mode (ATM) networks, VP/VC establishment and bandwidth reservation can be separately performed. Fast Reservation Protocol (FRP), a recently proposed protocol, utilizes this unique feature of the ATM technology to accomplish an efficient use of bandwidth. In FRP, a protocol data unit is called a burst, and a source requests the bandwidth reservation for each burst transmission on the established connection. In this paper, we provide an exact analysis for a class of FRP to obtain the burst delay distribution. Another feature of ATM is that the transmission rate can be set freely if it is admitted by the network. In our modeling, this feature is also incorporated in such a way that the requested bandwidth is reduced if the first attempt to reserve bandwidth is rejected by the network. Through numerical examples, appropriate values of control parameters such as the requested transmission rates are examined to show an effectiveness of FRP. The influences of the propagation delay and overhead due to control cells are also investigated by introducing an approximate technique.