Adjuvant activity of muramyl dipeptide derivatives to enhance immunogenicity of a hantavirus-inactivated vaccine

The adjuvant effect of two lipophilic derivatives of muramyl dipeptide (MDP), B30-MDP and MDP-Lys(L18), on the ability of an inactivated vaccine of B-1 virus (B-1 vaccine) to induce immune response against Hantavirus causing hemorrhagic fever with renal syndrome (HFRS) was examined. When mice were immunized subcutaneously (s.c.) twice at 2-week intervals with B-1 vaccine admixed with or without 100 micrograms mouse-1 of B30-MDP (B-1/B30-MDP) or MDP-Lys(L18) [B-1/MDP-Lys(L18)], mice immunized with B-1/B30-MDP as well as B-1/MDP-Lys(L18) showed significantly higher indirect fluorescent antibody (IFA) titers against HFRS virus than mice immunized with B-1 vaccine alone. Both mice treated with B-1/B30-MDP and B-1/MDP-Lys(L18) also exhibited significantly higher neutralizing antibody titers against HFRS virus than mice immunized with B-1 vaccine alone during 3-9 weeks after the primary immunization. The evaluation of antibody-producing cells by enzyme-linked immunospot (ELISPOT) assay on week 4 revealed that both MDP derivatives enhanced the number of HFRS virus-specific IgG1 and IgM antibody-producing cells. Furthermore, mice treated with B-1/B30-MDP as well as B-1/MDP-Lys(L18) showed a higher level of Th-2 type cytokines, IL-4 and IL-6, in sera than mice treated with B-1 alone. In an in-vitro analysis of T lymphocyte proliferation to baculovirus-expressed recombinant nucleocapsid protein (rNP) of Hantaan 76-118 strain, the splenocytes of mice treated with B-1/B30-MDP and B-1/MDP-Lys(L18) on week 4 showed a significantly higher proliferating activity than those treated with B-1 vaccine alone. In addition, when mice were immunized once with B-1 vaccine admixed with or without B30-MDP and MDP-Lys(L18) and followed by intrafootpad (i.f.) injection of B-1 vaccine on day 7, mice immunized with B-1/B30-MDP and B-1/MDP-Lys(L18) induced a higher delayed-type hypersensitivity (DTH) reaction than mice immunized with B-1 vaccine alone. These results suggest that B30-MDP and MDP-Lys(L18) are useful immunoadjuvants to enhance the ability of inactivated B-1 vaccine to induce a humoral and cellular response to HFRS virus.     

Epstein-Barr virus-positive multiple early gastric cancers and dysplastic lesions: a case report

Epstein-Barr virus (EBV) has been implicated as a causal virus of gastric cancer with episomal monoclonality, elevated antibodies and a unique morphologic expression in the early intramucosal stage, but the infection mechanisms have not been demonstrated. EBV has been shown only in the cancerous lesions by the highly sensitive EBV-encoded small RNA in situ hybridization (EBER-ISH) method, not in the dysplastic mucosa adjacent to the cancer. A case is presented of multiple EBV-positive gastric cancer and dysplastic epithelium observed in a 52-year-old man. Serial cut sections of the gastrectomy specimen showed four small cancerous lesions, three of which were EBER-positive, and three EBER-positive, minute, non-cancerous dysplastic lesions. The three cancerous lesions were intramucosal cancer, with one having minimal submucosal invasion forming a lymphoepithelioma-like histology. All of these EBER-positive cancerous and dysplastic lesions showed intense CD8 T-lymphocytic infiltration. There was no such findings in the EBV-negative cancerous lesion. It was concluded that EBV infection may occur in the epithelial cells of atrophic gastric mucosa, and progress to cancer with monoclonal expansion through the EBV-positive dysplastic change. Cytotoxic T-lymphocytic reactions can occur even in the dysplastic lesions. Multifocal EBV infection in the gastric mucosa may occur and, if necessary, total gastrectomy is recommended in such a case.     

Conductimetric titration of polyelectrolytes having sulfate and carboxyl groups

Summary Conductimetric titration of polyelectrolyte solutions was carried out to determine the contents of sulfate and carboxyl groups. In the mixtures of poly(acrylic acid) and poly(vinyl sulfate), and of alginic acid and dextran sulfate, the contents of sulfate and carboxyl groups observed by the conductimetric titration were in agreement with those derived from the concentration of the original homopolymers. This method was applied to a viscous polysaccharide from red algae, funoran, which contains both the sulfate and carboxyl groups. These results suggested that this method is applicable to either the samples consisting of the mixture of homopolymers or those of copolymers containing both ionic species.     

Development of forging process design to close internal voids

In this study, the closing behavior of internal voids was examined by a deformation analysis involving the 2-D finite element method (FEM), which simulates voids in steel ingots in the compression process (upset process). In the compression process, a model experiment that uses internal voids was carried out to confirm the accuracy of the deformation analysis. By comparing the model experiment with the analytical results, it was confirmed to simulate the internal void behavior by this analysis. The relationship between the reduction ratio and the void shape/void position was investigated by the analysis. In the forging process, the closing evaluation value of internal voids (Q value) was calculated by a model experiment and 3-D FEM. Using the analysis results, a limit value of the closing behavior of voids was quantified, and it is now understood that the voids close at more than Q = 0.21. In addition, the forging process of filling the above-mentioned value was designed by the Taguchi method. The predicted Q value in the case of using the Taguchi method almost corresponds to the value calculated by the deformation analysis. It was clarified that the process is capable of being designed simply.     

Isolation of sake yeast mutants producing a high level of ethyl caproate and/or isoamyl acetate

In the case of sake, ethyl caproate and isoamyl acetate are considered to be closely associated with flavor. Various mutant yeast strains producing a higher level of flavor compounds (ethyl caproate and/or isoamyl acetate) than the parent strain were isolated by ethyl methane sulfonate treatment followed by global selection. Two of the mutants obtained also showed a high malate productivity. These mutants would be promising for practical sake fermentation.     

Efficient discovery of optimal word-association patterns in large text databases

We study efficient discovery of proximity word-association patterns, defined by a sequence of strings and a proximity gap, from a collection of texts with the positive and the negative labels. We present an algorithm that finds alld-stringsk-proximity word-association patterns that maximize the number of texts whose matching agree with their labels. It runs in expected time complexityO(k ^d−1n log ^d n) and spaceO(k ^d−1n) with the total lengthn of texts, if texts are uniformly random strings. We also show that the problem to find one of the best word-association patterns with arbitrarily many strings in MAX SNP-hard. Shinichi Shimozono, Ph.D.: He is an Associate Professor of the Department of Artificial Intelligence at Kyushu Institute of Technology Iizuka, Japan. He obtained the B.S. degree in Physics from Kyushu University, awarded M.S. degree from Graduate School of Information Science in Kyushu University, and his Dr. Sci. degree in 1996 from Kyushu University. His research interests are primarily in the design and analysis of algorithms for intractable problems. Hiroki Arimura, Ph.D.: He is an Associate Professor of the Department of Informatics at Kyushu University, Fukuoka, Japan. He is also a researcher with Precursory Research for Embryonic Science and Technology, Japan Science and Technology Corporation (JST) since 1999. He received the B.S. degree in 1988 in Physics, the M.S. degree in 1979 and the Dr.Sci. degree in 1994 in Information Systems from Kyushu University. His research interests include data mining, computational learning theory, and inductive logic programming. Setsuo Arikawa, Ph.D.: He is a Professor of the Department of Informatics and the Director of University Library at Kyushu University, Fukuoka, Japan. He received the B.S. degree in 1964, the M.S. degree in 1966 and the Dr.Sci. degree in 1969 all in Mathematics from Kyushu University. His research interests include Discovery Science, Algorithmic Learning Theory, Logic and Inference/Reasoning in AI, Pattern Matching Algorithms and Library Science. He is the principal investigator of the Discovery Science Project sponsored by the Grant-in Aid for Scientific Research on Priority Area from the Ministry of ESSC, Japan.     

Quadruped walking robots at Tokyo Institute of Technology

I(Hirose) was walking along a mountain path near Mt. Fuji on a summer day of 1976, when I found a daddy long-legs walking on the ground. I picked it up in my palm and allowed it to walk over my fingers, and the bug walked effortlessly even over finger-made obstacles ten times larger than its own body. While I was watching the motion of the bug, I started to have the desire to make bigger multilegged walking robots, which can walk over large buildings. This was the beginning of our study of walking robots, which was to last for more than 30 years.