Showing papers by "Gifu University of Medical Science published in 2007"

Local immune response to respiratory syncytial virus infection is diminished in senescence-accelerated mice.

Abstract: The effect of ageing on the local defence system against respiratory syncytial virus (RSV) infection was investigated using an aged mouse model of the senescence-accelerated mouse (SAM) strain P1. Following intranasal infection with RSV, SAM-P1 mice showed a marked loss in weight, with elevated virus growth in the lungs and prolonged virus shedding. The increased susceptibility to RSV infection was associated mainly with diminished cellular immunity by local virus-specific cytotoxic T lymphocytes and natural killer cells. The deficiency in cellular immune responses was due to a lack of clonal expansion of CD4+ and CD8+ T lymphocytes, together with an imbalance of T-helper type 1 (Th1)/Th2 cytokine production in the respiratory tract, including the lungs. Furthermore, the production of virus-specific local IgA antibody was restrained. Prolonged virus loading in the lungs of SAM-P1 mice caused a massive infiltration of CD16+/32+ inflammatory cells, which was one factor responsible for severe pneumonia. The adoptive transfer of immune-competent spleen cells achieved an appreciable protection for SAM-P1 mice against RSV challenge infection. These results suggested that age-related immune dysfunction, especially defects in cellular immune responses, accounts for the increased morbidity and mortality in RSV infection of the elderly.

Respiratory syncytial virus protects against the subsequent development of Japanese cedar pollen-induced allergic responses

Abstract: Respiratory syncytial virus (RSV) infection has been hypothesized to be a risk factor for the development of allergy and asthma, but epidemiologic studies in humans still remain inconclusive. The association between RSV infection and allergic diseases may be dependent on atopic background and previous history of RSV infection. In this study, the influence of the timing of RSV infection on the development of Japanese cedar pollen (JCP)-induced allergic responses was examined. BALB/c mice were intranasally infected with RSV before or after sensitization to JCP. Production of cytokines in the culture fluid of lung parenchyma cells and the level of antigen-specific antibodies in the serum were determined. It became clear that JCP was a strong inducer for the elicitation of Th2-type responses, characterized by production of interleukin (IL)-4 and IL-5 in the lung and JCP-specific IgE antibody in the serum. RSV infection, however, suppressed JCP-induced allergic responses by decreasing the production of Th2-like cytokines and Th2-type antibodies. This phenomenon was observed more clearly in the groups that were infected with RSV, 2 weeks or 2 days before sensitization to JCP. The inhibitory mechanism of RSV infection seems to be due to RSV-induced Th1 type dominant environment, which down-regulated the Th2-type responses subsequently induced by allergen sensitization. On the other hand, JCP-inoculation altered RSV-induced immune responses to shift from Th1- to Th2-type dominance, by inhibiting RSV-induced Th1-like cytokine production. These data provide evidence that under a certain condition, RSV infection may play a protective role in JCP-induced allergic responses.

Readability of character size for car navigation systems

Abstract: An experiment was conducted on the ease with which a car navigation system could be read by elderly, middle-aged and young people. 127 subjects (19-76 years of age) evaluated ease of reading of the displayed characters. The experiment evaluated characters displayed on a liquid crystal display (LCD) similar to those used in car navigation systems, and evaluated readability in 9 stages. Five character sizes for traffic terms and two languages (Japanese and English) were used in the experiment. The experiment was conducted with the LCD in 2 positions: directly in front of the subject and diagonal to the left (about 30 degrees). The results showed that the directly frontward position was significantly more readable than the position of diagonal to the left.

Evaluation of High Quality LCDs Displaying Moving Pictures, on the Basis of the Form Obtained from Statokinesigrams

Abstract: Optically compensated bend (OCB) mode liquid crystal display (LCD) panels are newly developed displays that have excellent moving picture quality, which is almost equivalent to that of a cathode ray tube (CRT). A high performance, with a brightness of 600 cd/m 2 and a contrast ratio of 600:1, was obtained by using the pseudo-impulse driving method to insert a black period between two continuous frames; further, the blinking backlight method was used. By measuring the centre of gravity of the human body, we compared statokinesigrams obtained from subjects viewing moving maps on OCBs and on conventional model displays. The results suggest that OCBs are better than conventional displays for scrolling map images such as those in car-navigation systems.

Fetal calf serum inhibits virus genome expression in Madin-Darby canine kidney cells persistently infected with influenza A virus

Abstract: A cell line of Madin-Darby canine kidney (MDCK) cells persistently infected with human influenza A virus has been established and designated as MDCK-IVpi cells. Production of progeny virus in MDCK-IVpi cells was suppressed when the cells were incubated in the presence of 10% fetal calf serum (FCS). FCS impaired virus mRNA synthesis in MDCK-IVpi cells, which resulted in a scarcity of virus proteins for virion formation. However, MDCK-IVpi cells well supported the growth of superinfecting heterologous influenza viruses, even in the presence of FCS. A certain fetuin-like substance in FCS might be responsible for the observed inhibition of virus replication.

An Experimental Study on the Effects of Exitability and Correctability on Electronic Negotiation

Abstract: The purpose of the present study was to examine via a laboratory experiment the effects of two features of electronic negotiation, correctability and exitability, on negotiation processes and outcomes. We define correctability as the negotiator's ability to revise messages before transmitting them to the other party, thus prompting informational and social elaboration. The opportunity to exit the negotiation that the use of the electronic medium creates, a phenomenon for which we have coined the term “exitability,” can give rise to the perception that electronic negotiation is inherently more unstable than face-to-face negotiation. In two experiments, we manipulated the exitability of one of the parties in three ways. In another experiment, we manipulated correctability in two ways. We found that increased exitability caused by the existence of a potential alternative party with whom to negotiate prompted participants to decrease their demands and to reach agreement more often. Increasing the correctability of messages enhanced their clarity and generated more trade-offs, thus leading to more frequent agreements.

Dynamics Analysis of Electrogastrography using Double-Wayland Algorithm

Abstract: The electrogastrography (EGG) is an abdominal surface measurement of the electric activity of the stomach. It is great clinical importance to record and analyze multi-channel EGGs, which provide more information on the propagation and co-ordination of gastric contractions. The aim of the study is to estimate the dynamics that generate electrogastrography Double-Wayland algorithm was applied to the analysis. As a result, all the components of multi-channel EGGs can be generated from a chaos process. We found 5 or 6 independent essential components from EGGs.