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Biomedical subjects

Hidekazu Nishimura

Publications and source records attributed to Hidekazu Nishimura.

At least 19 recordsLinked to original sources
PubMed2007

A nationwide epidemic of influenza C virus infection in Japan in 2004.

During the period from January to July 2004, a total of 131 influenza C viruses were detected by cell culture or reverse transcription-PCR (RT-PCR) from specimens that were obtained from children with acute respiratory symptoms in 10 prefectures across Japan. Influenza C virus was identified most frequently in the Miyagi (1.4%, 45 of 3,226 specimens) and Yamagata (2.5%, 31 of 1,263 specimens) prefectures, and the frequency in this year was the highest since 1990. Phylogenetic analysis of the hemagglutinin esterase gene of the 13 strains isolated in nine prefectures revealed that genetically similar strains belonging to the Kanagawa/1/76-related lineage dominantly spread throughout Japan. During the 2004 influenza season, influenza C virus coexisted with epidemics of influenza A virus (H3 strain), and 12 cases were identified from patients who had been diagnosed with influenza-like illness (7 were detected by RT-PCR, and 5 were detected by culture). A comparison of specimens that were found positive by culture with those found positive only by RT-PCR shows that the amount of virus in PCR-positive specimens tended to be lower than in isolation-positive specimens. Although the mean peak temperature in patients in the PCR-positive group was slightly lower, there were no significant differences in characteristics between specimens (i.e., kind of specimen, period from onset to specimen collection, age distribution of patients, and severity of illness). These results suggest that an epidemic of influenza C virus occurred on a national scale during this period and that RT-PCR can be an effective supplemental tool for the evaluation of clinical and epidemiological information.

Animals↗
PubMed2007

Reactivation of herpes simplex virus type 1 and varicella-zoster virus and therapeutic effects of combination therapy with prednisolone and valacyclovir in patients with Bell's palsy.

OBJECTIVES: To determine whether reactivation of herpes simplex virus (HSV) type 1 or varicella-zoster virus (VZV) is the main cause of Bell's palsy and whether antiviral drugs bring about recovery from Bell's palsy. STUDY DESIGN: Randomized, multicenter, controlled study. METHODS: One hundred fifty patients with Bell's palsy were enrolled in this study. The patients were randomly assigned to a prednisolone group or a prednisolone-valacyclovir group, in whom virologic examinations for HSV-1 and VZV were performed by simple randomization scheme in sealed envelopes. The recovery rates among various groups were analyzed using the Kaplan-Meier method and the Cox proportional hazards model. RESULTS: Reactivation of HSV-1, VZV, and both viruses was detected in 15.3%, 14.7%, and 4.0% of patients, respectively. There was no significant difference in recovery rates between the prednisolone group and the prednisolone-valacyclovir group, although recovery in the patients with HSV-1 reactivation tended to be higher in the prednisolone-valacyclovir group than in the prednisolone group. There was a significant difference in recovery among age groups and between individuals with complete and incomplete paralysis. CONCLUSIONS: Reactivation of HSV-1 or VZV was observed in 34% of the patients with Bell's palsy. The effect of combination therapy with prednisolone and valacyclovir on recovery was not significantly higher than that with prednisolone alone.

Acyclovir↗
PubMed2006

Antipyretic effect of Mao-to, a Japanese herbal medicine, for treatment of type A influenza infection in children.

Mao-to is a Japanese traditional herbal medicine which has been used since ancient times for the treatment of influenza-like illness. This study was conducted to evaluate the effect of oral Mao-to administration in children with type A influenza, in comparison to Oseltamivir. We performed a controlled trial of 60 children, from 5 months through 13 years of age, with fever and influenza-like symptom of up to 48 h duration. Diagnosis of influenza type A was performed by virus isolation or detection of a viral gene by RT-PCR. Patients assigned into the following 3 groups: oral Mao-to powder (TJ-27) 0.06 g/kg body wt./dose three times daily (n=17), Oseltamivir 2 mg/kg body wt./dose twice daily (n=18) or both oral Mao-to plus Oseltamivir (n=14). The median duration of fever after treatment was significantly shorter in the Mao-to and Mao-to plus Oseltamivir groups, compared with the Oseltamivir only group (15 h [95%CI 13.2-22.1] p<0.01; 18 h[15.2-27.7] p<0.05; 24 h[23.5-43.0], respectively). Oral Mao-to administration was effective in the control of fever due to type A influenza infection in children.

Administration, Oral↗
PubMed2006

Diagnosis of human respiratory syncytial virus infection using reverse transcription loop-mediated isothermal amplification.

Human respiratory syncytial virus (RSV) is a major causative agent of lower respiratory tract infections in children and the elderly. A reverse transcription-loop-mediated isothermal amplification (RT-LAMP) was developed assay to amplify the genome of RSV subgroups A and B, in order to improve current diagnostic methods for RSV infection. The primer sets for RT-LAMP were designed using highly conserved nucleotide sequences in the matrix protein region of subgroups A and B, and were specific for each subgroup. The RT-LAMP efficiency was compared to virus isolation and a commercially available enzyme immunoassay (EIA) for RSV detection (BD Directigen EZ RSV test), using nasopharyngeal aspirates from 59 children with respiratory tract infections. The RT-LAMP was specific for RSV and could not detect other respiratory pathogens. 61% (36/59) of children were positive by RT-LAMP, 34% (20/59) by viral isolation, and 56% (26/46) by EZ RSV. Of 16 specimens that were negative by both antigen detection and virus isolation, 12.5% (2/16) were RT-LAMP positive. These results suggest that the RT-LAMP is more sensitive than other methods used to detect RSV. The RT-LAMP assay developed in this study may be useful for diagnostic and epidemiological studies of RSV infection.

Base Sequence↗
PubMed2006

Clinical features of influenza C virus infection in children.

BACKGROUND: Seroepidemiological studies have revealed that influenza C virus is widely distributed globally. However, because the isolation of this virus is difficult, there have been few reports on its clinical features. METHODS: Between December 1990 and November 2004, 84,946 respiratory-tract specimens were obtained from patients < or = 15 years old. On the basis of the results of isolation of virus, we examined the clinical data on children infected with influenza C virus. RESULTS: Of 170 children infected with influenza C virus, 157 (92.4%) were < 6 years old. Fever (frequency, 90.0%), cough (frequency, 74.1%), and rhinorrhea (frequency, 61.8%) were the most frequent symptoms. The mean duration of fever was 2.88 days (standard deviation, 1.66 days). Of the 170 children, 29 were hospitalized, and 21 (72.4%) of these 29 had lower-respiratory-tract illness such as pneumonia, bronchitis, and bronchiolitis. The rate of hospital admission was significantly higher in children < 2 years old than in children 2-5 years old (30.4% vs. 11.9%; P = .0043). CONCLUSIONS: Influenza C virus is a significant cause of upper-respiratory-tract illness in children < 6 years old, and the risk of complications with lower-respiratory-tract illness is particularly high in children < 2 years old.

Adolescent↗
PubMed2005

Mechanisms of mucin production by rhinovirus infection in cultured human airway epithelial cells.

Mucus hypersecretion relates to exacerbations of bronchial asthma and chronic obstructive pulmonary disease (COPD) caused by rhinovirus (RV) infection. We examined the mechanisms of RV infection-induced mucin production in human tracheal surface epithelial cells and submucosal gland cells. RV14 up-regulated the mRNA expression of MUC2, MUC3, MUC5AC, MUC5B and MUC6, and increased MUC5AC and total mucin concentration in supernatants and lysates of the surface cells. An inhibitor of the nuclear factor kappaB caffeic acid phenylethyl ester, inhibitors of selective p44/42 mitogen-activated protein kinase-kinase PD98059 and U0126, and a selective Src inhibitor PP1 attenuated MUC5AC mRNA expression, and secretion and production of MUC5AC and total mucin glycoprotein in the surface cells. In the gland cells, RV14 also increased mRNA expression of MUC2, MUC5AC, MUC5B and MUC7, and the inhibitors attenuated the secretion of total mucin glycoprotein. Src-related p44/42 mitogen-activated protein kinase pathway may be associated with RV-induced mucin hypersecretion in human airways.

Aged↗
PubMed2005

The proton pump inhibitor lansoprazole inhibits rhinovirus infection in cultured human tracheal epithelial cells.

To examine the effects of lansoprazole, a proton pump inhibitor, on rhinovirus infection in airways, human tracheal epithelial cells were infected with a major subgroup of rhinoviruses, type 14 rhinovirus. Rhinovirus increased the mRNA expression of intercellular adhesion molecule-1 (ICAM-1) in the cells, the major rhinovirus receptor, and the content of the soluble form of ICAM-1 (sICAM-1) and cytokines in supernatants. Lansoprazole reduced supernatant titers and RNA of rhinovirus, the susceptibility to rhinovirus infection, the ICAM-1 mRNA production, the number and fluorescence intensity of acidic endosomes in the cells, and supernatants sICAM-1 and cytokine concentrations including interleukin-1beta. Antibody to interleukin-1beta reduced baseline and rhinovirus-induced ICAM-1 production. These results suggest that lansoprazole inhibits rhinovirus infection by reducing ICAM-1 via partly endogenous production of interleukin-1beta, and by blocking the rhinovirus RNA entry into the endosomes. Lansoprazole may modulate airway inflammation by reducing the production of cytokines and ICAM-1 in rhinovirus infection.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2005

Detection of human metapneumovirus from children with acute otitis media.

Nasal and middle ear specimens collected from children with acute otitis media were subjected to viral isolation and bacteria culture. All virus-negative specimens underwent reverse transcription polymerase chain reaction to detect human metapneumovirus. Three of 126 middle ear specimens were positive by this assay.

Acute Disease↗
PubMed2005

Detection of human coronavirus-NL63 in children in Japan.

Human coronavirus NL63 recently found in The Netherlands has been detected in Japan with a reverse transcription-polymerase chain reaction technique in clinical specimens from pediatric patients with respiratory symptoms. Of 419 specimens that were negative for common respiratory viruses, 5 were positive for human coronavirus NL63, and these specimens were all collected in the first 3 months of 2003.

Child↗
PubMed2005

Inflammatory and bronchospastic factors in asthma exacerbations caused by upper respiratory tract infections.

It is still uncertain how viral respiratory infections cause acute exacerbations of bronchial asthma, although several mechanisms have been proposed. We studied the relationship between the airway narrowing and the inflammatory and bronchospastic factors in peripheral venous blood and urine, in 30 patients with asthma at the exacerbations caused by upper respiratory tract infections (URTIs). Acute exacerbations caused decreases in peak expiratory flow rate (PEFR) in all 30 patients with asthma. Asthma exacerbations caused the rises in serum levels of interleukin-6, soluble intercellular adhesion molecule-1 and eosinophil cationic protein, concentrations of urinary leukotriene E4 and plasma histamine, compared with those in patients with asthma at a stable condition and those in 30 control subjects (p < 0.05). The values of PEFR at the exacerbations correlated with the levels of these factors. Treatment with oral glucocorticoids reversed the decreases in PEFR and the increases in these factors. At the onset of URTIs, rhinovirus and influenza type A virus were identified in 13 and 7 patients, respectively. Each of parainfluenza virus, adenovirus, and enterovirus was identified in one patient. These findings suggest that respiratory viral infections may cause acute asthma exacerbations via the production of mediators that induce inflammation and bronchospasm.

Acute Disease↗
PubMed2004

Productive infection in the murine central nervous system with avian influenza virus A (H5N1) after intranasal inoculation.

The H5N1 type of influenza A virus isolated from human patients in 1997 has a characteristic hemagglutinin and was considered to be directly transmitted from birds. Although neuropathogenicity of this virus was not demonstrated in human autopsy cases, some experimental studies using mice have disclosed that this virus infects the central nervous system (CNS) after intranasal inoculation. In this study we focused on the topographical localization of virus-infected cells in the murine CNS after intranasal inoculation. We immunohistochemically examined virus-infected cells in mouse tissues using a rabbit antiserum recognizing the nucleoprotein of influenza A virus. The virus-infected cells appeared initially in the respiratory tract. Thereafter, the virus antigen-positive cells appeared in the olfactory system and the cranial nerve nuclei innervating the facial region. This suggests that this virus is principally transmitted from the nasal cavity to CNS through the cranial nerves. Neurons were frequently infected and glial and ependymal cells were also infected. Transneuronal transmission of the virus might play the important role of viral spread within the CNS.

Administration, Intranasal↗
PubMed2004

Enhanced virulence of influenza A viruses with the haemagglutinin of the 1918 pandemic virus.

The 'Spanish' influenza pandemic of 1918-19 was the most devastating outbreak of infectious disease in recorded history. At least 20 million people died from their illness, which was characterized by an unusually severe and rapid clinical course. The complete sequencing of several genes of the 1918 influenza virus has made it possible to study the functions of the proteins encoded by these genes in viruses generated by reverse genetics, a technique that permits the generation of infectious viruses entirely from cloned complementary DNA. Thus, to identify properties of the 1918 pandemic influenza A strain that might be related to its extraordinary virulence, viruses were produced containing the viral haemagglutinin (HA) and neuraminidase (NA) genes of the 1918 strain. The HA of this strain supports the pathogenicity of a mouse-adapted virus in this animal. Here we demonstrate that the HA of the 1918 virus confers enhanced pathogenicity in mice to recent human viruses that are otherwise non-pathogenic in this host. Moreover, these highly virulent recombinant viruses expressing the 1918 viral HA could infect the entire lung and induce high levels of macrophage-derived chemokines and cytokines, which resulted in infiltration of inflammatory cells and severe haemorrhage, hallmarks of the illness produced during the original pandemic.

Adolescent↗
PubMed2004

Genetic diversity of influenza B virus: the frequent reassortment and cocirculation of the genetically distinct reassortant viruses in a community.

To characterize the genetic diversity of influenza B viruses isolated during one influenza season, the antigenic and genetic relationships among 20 strains of influenza B virus isolated in February and March 2001 at one pediatric clinic in Yamagata City, Japan, were investigated. The HA gene and seven other gene segments were phylogenetically divided into three distinct sublineages (Harbin/7/94-, Tokyo/6/98-, and Shiga/T30/98-related lineage) of the Yamagata/16/88-like lineage. The NS genes of the viruses belonging to the Harbin/7/94-related lineage have additional three nucleotides at positions 439-447, and were phylogenetically distinguishable from those of the currently circulating Yamagata/16/88- and Victoria/2/87-like lineages, but were closely related to that of the Yamagata/16/88-like lineage isolated before 1994. Moreover, four strains of influenza B virus isolated in the same community between 2002 and 2003 were further examined. Phylogenetic analysis revealed that a virus of Victoria/2/87-like lineage isolated in 2003 had acquired the NA, NS, M, and PA gene segments from a Shiga/T30/98-like virus, and two strains of Harbin/7/94-related lineage had acquired the various gene segments from Shiga/T30/98-like virus through a reassortment event. These results indicate that genetically distinct multiple viruses can combine to cause an influenza B epidemic in a community and that the frequent reassortment among these viruses plays a role in generating the genetic diversity of influenza B viruses.

Adolescent↗
PubMed2004

Relationship between respiratory syncytial virus infection and acute otitis media in children.

BACKGROUND: Respiratory syncytial virus (RSV) is among the major causes of respiratory tract infection in infants and young children, and concomitant acute otitis media (AOM) often develops. However, there are only a few reports about AOM associated with RSV infection. METHODS: Two hundred and thirty children who were diagnosed as having RSV infection were studied by enzyme immunoassay (Testpack RSV) at the Department of Pediatrics of Tohoku Rosai Hospital from 1 November 2001 to 31 October 2002. In the patients with AOM, bacterial culture and detection of RSV antigen in the middle ear fluid (MEF) by enzyme immunoassay were performed, and the outcome was investigated. RESULTS: Among the 230 children, 120 (52.2%) were found to have AOM. In children under 2 years of age, the incidence of AOM was significantly higher (73.1%) than in the older children (29.7%). RSV antigen was positive in the MEF of 36 out of 52 patients with AOM (69.2%). In 24 of the 46 patients in whom both RSV antigen detection and bacterial culture of MEF were performed, RSV antigen was detected and bacterial culture was negative. Although the outcome of the first episode of AOM following RSV infection was favorable, relapse was observed in 31% of the patients. CONCLUSION: These results confirm that patients with RSV infection have a high risk of AOM, especially children younger than 2 years of age, and suggest that RSV may be a direct cause of AOM at least in the early stage of infection with this virus. The necessity of performing careful follow-up of AOM after resolution of symptoms is suggested because relapse is common.

Acoustic Impedance Tests↗
PubMed2003

Effects of rhinovirus infection on the adherence of Streptococcus pneumoniae to cultured human airway epithelial cells.

To examine the effects of rhinovirus (RV) infection on the adherence of Streptococcus pneumoniae to human tracheal epithelial cells, cells were infected with RV-14, and S. pneumoniae were added to the culture medium. The number of S. pneumoniae adhering to epithelial cells increased after RV infection. Y-24180, a specific inhibitor of the platelet-activating factor receptor (PAF-R); PAF; and the pyrrolidine derivative of dithiocarbamate, an inhibitor of transcription factor nuclear factor-kappaB (NF-kappaB), decreased the number of S. pneumoniae adhering to cells after RV-14 infection. RV-14 infection increased PAF-R expression and the activation of NF-kappaB and promoter-specific transcription factor 1. These findings suggest that RV-14 infection stimulates S. pneumoniae adhesion to airway epithelial cells via increases in PAF-Rs that are partly mediated through activation of transcription factors. Increased adherence of S. pneumoniae may be one of the reasons that pneumonia develops after RV infection.

Bacterial Adhesion↗