Publications by authors named "Ken-Ichiro Yamada"

Tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein, epsilon polypeptide (YWHAE), on chromosome 17p13.3, has been shown to play a crucial role in neuronal development. The deletion of YWHAE, but not platelet-activating factor acetylhydrolase, isoform 1b, subunit 1 (PAFAH1B1), underlies a newly recognized neurodevelopmental disorder, characterized by significant growth retardation, developmental delay/intellectual disability (DD/ID), distinctive facial appearance, and brain abnormalities.

View Article and Find Full Text PDF

Objective: Acute otitis media (AOM) is one of the most common complications of viral respiratory tract infections in children, but the role of each virus is still to be elucidated. We analyzed AOM associated with infection by cytomegalovirus (CMV), which is known as one of the major causes of viral respiratory tract infection.

Methods: Four hundred and ninety-five children (292 boys and 203 girls) diagnosed as having AOM in 2002 were studied.

View Article and Find Full Text PDF

Background: Molecular epidemiology of dengue viruses in endemic countries have been reported, but few were reported on the imported dengue cases among travelers. We analyzed dengue viruses isolated from imported dengue cases in Japan who were infected while traveling in endemic regions of the world.

Method: We sequenced the complete envelope (E) gene of 33 dengue virus strains isolated from patients returning from Asia, Oceania, South Pacific islands, and South America to Japan where no domestic dengue virus infection occurs.

View Article and Find Full Text PDF

To describe the clinical features of dengue cases in Japan, a retrospective study was conducted on 62 laboratory-confirmed Japanese dengue cases presented to Tokyo Metropolitan Komagome Hospital between 1985 and 2000. Age distribution was from 18 to 62 years old (mean, 31.5 years).

View Article and Find Full Text PDF

The fluorogenic TaqMan reverse transcriptase PCR (RT-PCR) assay was developed for detecting each of the dengue virus (DV) types 1 to 4. DV genome was detected in all the 35 serum samples from confirmed dengue cases by the TaqMan RT-PCR, although it was not detected in 13 and 21% by conventional type-specific and cross-reactive RT-PCR, respectively.

View Article and Find Full Text PDF

The effect of mouse brain-derived, inactivated Japanese encephalitis (JE) vaccine on West Nile virus (WNV) infection was examined using a murine model. Mice were immunized with JE vaccine twice and challenged with lethal doses of WNV. When mice were intracranially challenged with WNV, none of the immunized mice were protected.

View Article and Find Full Text PDF

Titers of antibodies to infecting dengue virus serotypes determined by serum neutralization assay were higher than those of antibody to Japanese encephalitis (JE) virus in Japanese dengue patients after disease day 8. Titers of antibody to dengue virus antigens determined by hemagglutination inhibition (HI) assay were higher in only 1 of 23 serum specimens after disease day 11. Thus, the neutralization test is more reliable than the HI test for serological diagnosis of dengue in countries where JE vaccination is widely used or JE is endemic.

View Article and Find Full Text PDF

Entry of Japanese encephalitis virus (JEV) into cells was analysed by using the vertebrate cell line Vero. Vero cells were treated with chlorpromazine, nystatin or cytochalasin D, which inhibit clathrin- and caveola-dependent endocytosis, and macropinocytosis of the cells, respectively. Productive JEV infection was inhibited by pretreatment with chlorpromazine; the number of JEV antigen-positive cells was less than one-fifth of that in untreated cultures, but was not significantly decreased by pretreatment with nystatin or cytochalasin.

View Article and Find Full Text PDF

We report three dengue fever cases, infected during a group tour to the Philippines. A 58-year old male experienced sudden onset of high fever 5 days after returning to Japan, followed by rash and thrombocytopenia. The other 2 cases experienced similar symptoms.

View Article and Find Full Text PDF

A58-year-old man suffered from acute disseminated encephalomyelitis (ADEM) after dengue fever. ADEM has not been described as the cause of neurological complications in dengue fever. However, the increasing use of magnetic resonance imaging in endemic areas may help to identify ADEM as being responsible for neurological complications in dengue fever.

View Article and Find Full Text PDF

The immunogenicity of a Japanese purified chick embryo cell culture rabies vaccine (PCECV) was examined. Serum samples were obtained from 86 subjects after pre-exposure or post-exposure prophylaxis. Rabies antibody titres were determined by neutralization test and enzyme-linked immunosorbent assay (ELISA).

View Article and Find Full Text PDF

Three commercial dengue IgM test kits and 'in-house' IgM-capture enzyme-linked immunosorbent assay (ELISA) were examined for false positive reactions, using 49 serum samples from patients with autoimmune diseases. All the samples were found to be negative by the 'in-house' IgM-capture ELISA. Five samples were determined to be positive by the immunochromatographic test and three of the five samples were also found positive by one commercial IgM-capture ELISA kit.

View Article and Find Full Text PDF

Virus isolation is the most reliable evidence of infection. In the present study, we isolated virus from serum samples collected from confirmed dengue cases. When data were analyzed based on disease days, dengue viruses were isolated from 28 of 32 serum samples collected on disease day 5 or earlier.

View Article and Find Full Text PDF