Biomedical subjects

Kazuo Nishikawa

Publications and source records attributed to Kazuo Nishikawa.

7 recordsLinked to original sources

PubMed2006

Decrease in the allergenicity of Japanese cedar pollen allergen by treatment with positive and negative cluster ions.

BACKGROUND: Japanese cedar pollinosis is a severe allergic disease in Japan. The most effective means of decreasing allergic inflammation reactions is still avoidance of the aeroallergen. Recently, a novel air purification system using positively and negatively charged cluster ions was developed to create comfortable living environments. We aimed to assess the ability of existing technology to lower allergenicity of Japanese cedar pollen. METHODS: A Japanese cedar pollen extract was nebulized from the top of a cylindrical container with 2 or 4 ion-generating devices. The extract in a mist was passed through the space filled with or without plasma cluster ions for 90 s, and the ion-treated or nontreated extract was then collected in a Petri dish at the bottom of the container. RESULTS: The ion-exposed extract was significantly diminished in its reactivities to anti-Cry j 1 or anti-Cry j 2 antiserum and to human allergic sera IgE on ELISA. SDS-PAGE analysis revealed that ion exposure induced protein degradation in the pollen extract. Similarly, the ion treatment impaired about 80% of the binding to pooled sera IgE from patients allergic to Japanese cedar pollen on ELISA inhibition. Furthermore, intracutaneous and conjunctival reaction tests showed a remarkable diminution in the allergenicity of the ion-irradiated extract. CONCLUSION: Ion irradiation resulted in a remarkable decrease in in vitro and in vivo allergenicities of atomized Japanese cedar pollen extracts.

Air Ionization↗

PubMed2006

Evaluation of apoptosis in Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis.

Epstein-Barr virus (EBV) is known to be a causative agent of hemophagocytic lymphohistiocytosis (HLH). To investigate association of apoptosis in the pathogenesis of EBV-associated HLH, the serum EBV loads, and serum concentrations of soluble tumor necrosis factor receptor 1 (sTNF-R1), soluble Fas ligand, and cytochrome c were examined in 15 patients with EBV-associated HLH and 24 patients with infectious mononucleosis (IM). Levels of sTNF-R1 are known to reflect the biological activity of TNF-alpha and cytochrome c is a specific marker of apoptosis. EBV loads, and concentrations of sTNF-R1 and cytochrome c were significantly higher in patients with EBV-associated HLH than in patients with IM. On the other hand, there were no statistically significant differences in the concentrations of soluble Fas ligand. In patients with EBV-associated HLH, EBV loads, concentrations of sTNF-R1, and cytochrome c were correlated with each other. These results suggest that apoptosis, which is dependent on the EBV load and could be mediated by TNF-alpha, plays a major role in the pathophysiology of EBV-associated HLH.

Apoptosis↗

PubMed2006

Analysis of gene-expression profiles by oligonucleotide microarray in children with influenza.

In order to clarify the mechanism of the host response to influenza virus, gene-expression profiles of peripheral blood obtained from paediatric patients with influenza were investigated by oligonucleotide microarray. In the acute phase of influenza, 200 genes were upregulated and 20 genes were downregulated compared with their expression in the convalescent phase. Interferon-regulated genes, such as interferon-induced protein with tetratricopeptide repeats 2 (IFIT2) and vipirin, were strongly upregulated in the acute phase. Gene ontology analysis showed that immune response genes were highly overrepresented among the upregulated genes. Gene-expression profiles of influenza patients with and without febrile convulsion were also studied. In patients with febrile convulsion, 22 genes were upregulated and five were downregulated compared with their expression in patients without febrile convulsion. These results should help to clarify the pathogenesis of influenza and its neurological complications.

Acute Disease↗

PubMed2005

Association of cytomegalovirus with infantile hepatitis.

Infantile hepatitis is occasionally seen in apparently healthy children. In most cases, the etiology of the infection is uncertain. However, cytomegalovirus (CMV), Epstein-Barr virus (EBV), human herpesvirus-6 (HHV-6), human herpesvirus-7 (HHV-7), human parvovirus B19, and TT virus (TTV) are considered to be associated with hepatitis in children. The objective of this study was to investigate the correlations between these viruses and infantile hepatitis. Twenty-six children from 1 to 24 months old (median age, 7 months) who had liver dysfunction of unknown etiology were enrolled in this study. Plasma samples were examined by a real-time PCR assay for CMV, EBV, HHV-6, HHV-7, parvovirus B19, and TTV DNA. The DNA of CMV was detected in the plasma of four patients (15.4%) and was detected significantly more often in the patient group than in the control group. The CMV-infected patients were 1 to 3 months old, which was significantly younger than the remaining patients. The serological findings did not always correlate with the results of the real-time PCR assay. The DNA of TTV was detected in four patients (15.4%), while human parvovirus B19 DNA was detected in three (11.5%). However, the detection frequencies of these viral DNAs were not significantly different from those in the control groups, and some of these patients had co-infections. These results indicate that CMV might be one of the major pathogens responsible for infantile hepatitis; however, serological tests have limited utility for the diagnosis of CMV infection in young children.

Alanine Transaminase↗

PubMed2004

Compaction of TiO2 suspension utilizing hydrophilic/hydrophobic transition of cationic thermosensitive polymers.

Compaction of TiO2 suspended particles utilizing the hydrophilic/hydrophobic transition of a cationic thermosensitive copolymer of N-isopropylacrylamide (NIPAM) and N-dimethylaminopropylacrylamide (DMAPAA) was examined. The surface of suspended TiO2 particles were sufficiently covered with the adsorbed polymer molecules at room temperature, and the suspension was subsequently heated above the transition temperature of the polymer. The thrusting motion of a plunger was used in order to provide an adequate mechanical force to compact the TiO2 suspended particles. The transition temperature was dependent on the DMAPAA content in the copolymer and the pH of the suspension. The transition temperature increased with increasing DMAPAA content and decreased with increasing pH. While suspended TiO2 particles were not compacted with poly(NIPAM), hard compacted sludge was readily obtained for cationic copolymer even if the content of DMAPAA groups was as low as 0.23 mol%. Furthermore, residual polymer molecules in the supernatant were not detected even if the polymer dosage was increased. These findings were attributed to the hydrophobic interaction of thermosensitive copolymer molecules adsorbed on TiO2 particles.

Journal Article↗

PubMed2002

Detection of herpesvirus DNA in the serum of immunocompetent children.

The DNA of herpesviruses such as Epstein-Barr virus (EBV), cytomegalovirus (CMV), human herpesvirus-6 (HHV6), and human herpesvirus-7 (HHV7) has been detected in the serum of patients with primary infection or with immunosuppression. However, it is unknown how frequently herpesvirus DNA can be detected in the serum of immunocompetent children, or whether the detection of herpesvirus DNA indicates an active infection or virus-related diseases. Using a real-time polymerase chain reaction assay, attempts were made to detect herpesvirus DNA in the serum of 176 ambulatory children who visited a hospital for various reasons. EBV was detected in 4 (2.2%), HHV6 in 4 (2.2%), and HHV7 in 2 (1.1%) of 176 children, but CMV was not detected. Of the 10 positive patients, only 4 were considered, by virtue of clinical and serological characteristics, to have primary infections. The other 4 positive patients had other infections, such as mycoplasma and salmonella. Although herpesvirus DNA could be detected in the serum of immunocompetent children, there was not always a relationship between clinical manifestations and the detection of virus DNA. When herpesvirus DNA is detected in the serum, a careful interpretation is necessary to diagnose a primary infection or a virus-associated disease.

Antibodies, Viral↗

PubMed2002

Viral load in Epstein-Barr virus-associated hemophagocytic syndrome.

The viral load in peripheral blood from patients with Epstein-Barr virus (EBV)-associated hemophagocytic syndrome was measured by real-time quantitative PCR and compared with that in infectious mononucleosis. Patients with EBV-associated hemophagocytic syndrome generally had larger viral burdens, although it was difficult to differentiate EBV-associated hemophagocytic syndrome from infectious mononucleosis simply by viral load. The difference in viral load seemed to be clearer in peripheral blood mononuclear cells than in plasma.

Adult↗