Comprehensive analysis and characterization of the TCR alpha chain sequences in the common marmoset.

The common marmoset (Callithrix jacchus) is useful as a nonhuman primate model of human diseases. Although the marmoset model has great potential for studying autoimmune diseases and immune responses against pathogens, little information is available regarding the genes involved in adaptive immunity. Here, we identified one TCR alpha constant (TRAC), 46 TRAJ (joining), and 35 TRAV (variable) segments from marmoset cDNA.

Chikungunya fever from Malaysia.

An adult Malaysian woman returned to Japan from Kuala Lumpur and had onset of dengue fever-like symptoms including high fever, malaise and arthritis in early January 2009. Serum obtained on the following day was tested at the National Institute of Infectious Diseases in Tokyo, where it was determined to be positive for chikungunya virus (CHIKV) RNA. IgM antibody against CHIKV was negative on January 6 and sero-converted to be positive on January 14, confirming a recent CHIKV infection.

A case of chikungunya fever imported from India to Japan, follow-up of specific IgM and IgG antibodies over a 6-month period.

Chikungunya fever is an arboviral disease caused by chikungunya virus. A 37-year-old Japanese male visited India and developed fever, myalgia, rash, and persisting systemic arthralgia, the latter of which persisted for more than 2 months. The patient was diagnosed with chikungunya fever by virological and serological examinations.

Discrepancy in dengue virus neutralizing antibody titers between plaque reduction neutralizing tests with Fcgamma receptor (FcgammaR)-negative and FcgammaR-expressing BHK-21 cells.

Protective immunity against dengue virus (DENV) is best reflected by the presence of neutralizing antibodies. The conventional plaque reduction neutralizing test (PRNT) is performed using Fcgamma receptor (FcgammaR)-negative cells. Because FcgammaR plays a key role in antibody-dependent enhancement, we examined neutralizing antibody titers of mouse monoclonal antibodies and human serum samples in PRNTs using FcgammaRIIA-negative and FcgammaRIIA-expressing BHK cells.

A single mutation in the Japanese encephalitis virus E protein (S123R) increases its growth rate in mouse neuroblastoma cells and its pathogenicity in mice.

We previously reported that the Japanese encephalitis virus (JEV) strain Mie/41/2002 has weak pathogenicity compared with the laboratory strain Beijing-1. To identify the determinants of its growth nature and pathogenicity, we produced intertypic viruses, rJEV(EB1-M41), rJEV(nEB1-M41) and rJEV(cEB1-M41), which contained the entire, the N-terminal, and the C-terminal half, respectively, of the Beijing-1 E region in the Mie/41/2002 background. The growth of rJEV(EB1-M41) in mouse neuroblastoma N18 cells and virulence in mice were similar to those of Beijing-1.

Chikungunya virus isolated from a returnee to Japan from Sri Lanka: isolation of two sub-strains with different characteristics.

A large-scale epidemic of chikungunya (CHIK) fever occurred in several Indian Ocean islands in 2004 and spread to India and Sri Lanka. In December 2006, a returnee to Japan from Sri Lanka developed an acute febrile illness. The patient was confirmed to have CHIK fever after reverse transcription-polymerase chain reaction, and specific IgM and IgG detection.

Development of an antibody-dependent enhancement assay for dengue virus using stable BHK-21 cell lines expressing Fc gammaRIIA.

Dengue virus (DENV) causes a wide range of symptoms, from mild febrile illness, dengue fever (DF), to severe life threatening illness, dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). Subneutralizing concentrations of antibody to DENV enhance DENV infection in Fc gammaR positive cells. This phenomenon is known as antibody-dependent enhancement (ADE).

Involvement of the Fc gamma receptor IIA cytoplasmic domain in antibody-dependent enhancement of dengue virus infection.

Sub-neutralizing concentrations of antibody to dengue virus (DENV) enhance DENV infection of Fc gamma receptor-expressing cells. This phenomenon, referred to as antibody-dependent enhancement (ADE), has been hypothesized to be responsible for the severe form of DENV infection, including dengue haemorrhagic fever and dengue shock syndrome. To analyse further the mechanisms of ADE in vitro, this study introduced a series of cytoplasmic mutants into human Fc gammaRIIA.

Effects of the number of amino acid residues in the signal segment upstream or downstream of the NS2B-3 cleavage site on production and secretion of prM/M-E virus-like particles of West Nile virus.

Expression of genes for precursor M (prM) and envelope (E) proteins of West Nile virus (WNV) leads to the production of small, capsidless, and non-infectious virus-like particles (VLPs) possessing the E antigen which is responsible for viral entry and immune protection. It has been reported that processing of the secretion signal affects viral release. We examined the secretion efficiency of VLPs into the culture medium from RK13 or 293T cells transfected with expression vectors for prM and E proteins of WNV which were constructed to comprise different lengths of signal peptides upstream of the prM-E domain.

Mechanism of introduction of exogenous genes into cultured cells using DEAE-dextran-MMA graft copolymer as non-viral gene carrier.

Comparative investigations were carried out regarding the efficiency of introduction of exogenous genes into cultured cells using a cationic polysaccharide DEAE-dextran-MMA (methyl methacrylate ester) graft copolymer (2-diethylaminoethyl-dextran-methyl methacrylate graft copolymer; DDMC) as a nonviral carrier for gene introduction. The results confirmed that the gene introduction efficiency was improved with DDMC relative to DEAE-dextran. Comparative investigations were carried out using various concentrations of DDMC and DNA in the introduction of DNA encoding luciferase (pGL3 control vector; Promega) into COS-7 cells derived from African green monkey kidney cells.

A new application of photocatalysts: synthesis of nano-sized metal and alloy catalysts by a photo-assisted deposition method.

Supported Pd catalysts were synthesized using various semiconductor materials by a photo-assisted deposition method under UV-light irradiation. The Pd precursor was deposited and partially reduced by the direct interaction with the photo-excited state of the semiconductor materials, and subsequently transformed into metal particles by H(2) reduction. CO adsorption and Pd K-edge XAFS measurements demonstrated that the mean diameter of the deposited Pd particles can be controlled by the type of employed semiconductor materials.

Intraoperative assessment of coronary bypass graft to posterior descending artery by means of transesophageal echocardiography.

Intraoperative transesophageal echocardiography (TEE) assessment of coronary artery graft anastomosed to posterior descending artery (PDA) was evaluated. Twenty-one patients with a saphenous vein (SV) graft (n=17) or right gastroepiploic artery (RGEA) graft (n=4) anastomosed to the PDA were examined. In the transgastric mid short-axis view, the graft was depicted as an echo-free zone between the right ventricle and diaphragm.

[Flavivirus encephalitis].

The member of the genus Flavivirus family Flaviviridae are arthropod-transmitted viruses. This genus includes vector-borne neurotropic viruses such as the tick-borne encephalitis virus serocomplex and the Japanese encephalitis virus serocomplex. Flavivirus encephalitis is the generic term for encephalitis caused by viruses belonging to this genus.

Plasmodium falciparum: development and validation of a measure of intraerythrocytic growth using SYBR Green I in a flow cytometer.

Reliable analytical techniques to test growth-promoting and antimalarial efficacy on plasmodia are very important. Flow cytometry (FCM) offers the possibility to study developmental stages of intraerythrocytic growth of malaria parasites using nucleic acid staining. To analyze the growth of Plasmodium falciparum SYBR Green I was introduced as an intercalating dye with FCM for the 488nm line of an argon laser.

Japanese encephalitis: surveillance and elimination effort in Japan from 1982 to 2004.

Japanese encephalitis (JE) surveillance has been conducted since 1965 as a part of the National Epidemiological Surveillance of Vaccine Preventable Diseases in Japan. Over 1,000 JE cases were reported annually in the late 1960s. The number of JE cases has since markedly decreased, with less than 10 cases reported annually from 1992 to 2004.

[West Nile fever/encephalitis].

West Nile virus (WNV), a member of the family Flaviviridae (genus Flavivirus), is a mosquito-borne virus first isolated in 1937 in the West Nile district of Uganda. The disease in humans is characterized by a dengue-like illness with fever, and a more severe form is characterized by central nervous system involvement, including encephalitis, meningitis, and myelitis. WN encephalitis was first reported in the Western Hemisphere in the summer of 1999, there was an outbreak in New York City.

Characterization of Asn130-to-Ala mutant of dengue type 1 virus NS1 protein.

The nonstructural protein 1 (NS1) of flavivirus has two N-glycosylation sites that are thought to be important for viral replication. Effects of NS1 glycosylation site mutations on viral replication have been reported in several flaviviruses, but the results have differed. In this report, we examined the role of glycosylation site of NS1 on the replication of dengue type 1 virus (DENV-1).

Peripheral blood mononuclear cells increase the permeability of dengue virus-infected endothelial cells in association with downregulation of vascular endothelial cadherin.

Plasma leakage is one of the characteristic features of dengue haemorrhagic fever. The interaction among peripheral blood mononuclear cells (PBMCs), dengue virus and endothelial cells was analysed in vitro. Human umbilical vein endothelial cells (HUVECs) were infected with dengue-2 virus (DV-2) at an m.

Vero cell-derived inactivated West Nile (WN) vaccine induces protective immunity against lethal WN virus infection in mice and shows a facilitated neutralizing antibody response in mice previously immunized with Japanese encephalitis vaccine.

A novel Vero cell-derived inactivated WN vaccine (WN-VAX) was prepared from virus strain NY99-35262. Two immunizations with WN-VAX induced high levels of neutralizing antibody to WN virus. All immunized mice were protected against challenge with a lethal dose of WN virus.

Accumulation of T-cells with selected T-cell receptors in the brains of Japanese encephalitis virus-infected mice.

Japanese encephalitis is a severe central nervous system (CNS) disease with a high case fatality rate in humans. We characterized T-cells infiltrating the brain after infection with Japanese encephalitis virus (JEV) in a mouse model and determined the clonality of the infiltrating T-cells by analyzing the sequences of complementary determining region 3 (CDR3) of the T-cell receptor. C3H/He mice died after intraperitoneal infection with the JaTH160 strain of JEV, demonstrating CNS degeneration and prominent T-cell infiltration.

Dengue virus type 2 isolated from an imported dengue patient in Japan: first isolation of dengue virus from Nepal.

We report the isolation of dengue virus type 2 from a dengue patient returning to Japan from Nepal in October, 2004. This is the first isolate of dengue virus in Nepal. According to nucleotide homology, the virus was closest to a dengue virus type 2 isolate from India.