Mikio Yoshioka

Detection of a novel DNA virus (TTV) sequence in peripheral blood mononuclear cells.

DNA sequences of a novel DNA virus (TTV) were examined in 81 peripheral blood mononuclear cell (PBMC) DNA samples from 48 children and 33 adults, 22 cord blood mononuclear cells (CBMC) DNA samples, and 7 autopsy liver tissue DNA samples by a hemi‐nested polymerase chain reaction (PCR). The PCR was carried out using the published primers (NG059, NG061, NG063) to amplify TTV DNA sequences. The sequences were detected in 4 of 81 (5%) PBMC DNA samples, in none of 22 (0%) CBMC DNA samples, and in 2 of 7 (29%) liver tissue DNA samples by direct gel analysis. The PCR‐amplified products were confirmed by direct sequencing. The sequencing showed considerable diversities, with differences of 0–55% in 6 TTV isolates, compared with the prototype sequence of TTV. These results suggest that TTV is a ubiquitous virus that produces asymptomatic infection in a large proportion of the general population without transfusion of blood‐derived products. To our knowledge, this is the first report describing the detection of TTV DNA sequences in PBMCs. J. Med. Virol. 58:174–177, 1999.

Detection of TT virus sequences in children with liver disease of unknown etiology.

DNA sequences of TT virus (TTV) in 55 serum samples taken from 20 children with liver disease of unknown etiology (16 with acute liver disease, 2 with fulminant hepatitis, and 2 with chronic liver disease) and from 35 healthy children as controls were examined by using the hemi‐nested polymerase chain reaction (PCR). The PCR was carried out using the established primers (NG059, NG061, NG063) to amplify TTV DNA sequences. The sequences were detected in 6 of the 20 patients (30.0%) with liver disease and in 5 of the 35 healthy children (14.2%) by direct gel analysis. There was no significant difference between the prevalence of liver disease patients and controls. However, both patients with fulminant hepatitis and both patients with chronic hepatitis had TTV DNA sequences. Four of the six TTV isolates from liver disease patients were genotype 1a, whereas only one of the five TTV isolates from controls was genotype 1a. Although the study population was small, it is possible that genotype 1a of TTV might be more pathogenic than other genotypes in children. J. Med. Virol. 62:104–108, 2000.

Heterogeneous, restricted patterns of Epstein-Barr virus (EBV) latent gene expression in patients with chronic active EBV infection

Epstein-Barr virus (EBV) has been shown to infect T lymphocytes and to be associated with a chronic active infection (CAEBV), which has been recognized as a mainly non-neoplastic T-cell lymphoproliferative disorder (T-cell LPD). The systemic distribution of EBV genomes was studied, by real-time PCR, in multiple tissues from six patients with CAEBV, including three patients with T-cell LPD, one patient with B-cell LPD and two patients with undetermined cell-type LPD. There were extremely high loads of EBV genomes in all tissues from the patients. This reflects an abundance of circulating and infiltrating EBV-infected cells and a wide variety of clinical symptoms in the affected tissues. We chose one sample from each patient that was shown by real-time PCR to contain a high load of EBV genomes and examined the expression of EBV latent genes by RT-PCR. EBER1 and EBNA1 transcripts were detected in all samples. Only one sample also expressed EBNA2, LMP1 and LMP2A transcripts in addition to EBER1 and EBNA1 transcripts. Two of the remaining five samples expressed LMP1 and LMP2A transcripts. One sample expressed LMP2A but not LMP1 and EBNA2 transcripts. Another sample expressed EBNA2 but not LMP1 and LMP2A transcripts. The other sample did not express transcripts of any of the other EBNAs or LMPs. None of the samples expressed the viral immediate-early gene BZLF1. These results showed that EBV latent gene expression in CAEBV is heterogeneous and that restricted forms of EBV latency might play a pathogenic role in the development of CAEBV.

Detection of Human Bocaviruses 1 to 4 from Nasopharyngeal Swab Samples Collected from Patients with Respiratory Tract Infections

ABSTRACT Human bocaviruses (HBoV) 1, 2, 3, and 4 (HBoV1-4) were detected in 132 (15.5%), 5 (0.6%), 3 (0.4%), and 5 (0.6%) of 850 nasopharyngeal swab samples collected from children with respiratory tract infections, respectively. Out of the 145 HBoV1-4-positive samples, 62 (42.8%) were codetected with other respiratory viruses.

Association of the prtF1 Gene (Encoding Fibronectin-Binding Protein F1) and the sic Gene (Encoding the Streptococcal Inhibitor of Complement) with emm Types of Group A Streptococci Isolated from Japanese Children with Pharyngitis

ABSTRACT A total of 66 clinical isolates of group A streptococci (GAS) were obtained from 66 Japanese children with pharyngitis. The prtF1 gene (encoding fibronectin-binding protein F1) and the sic gene (encoding the streptococcal inhibitor of complement) were present in 51 (77.3%) and 48 (72.7%) of the 66 isolates, respectively. These results indicated that a high prevalence of two virulence genes, prtF1 and sic, is characteristic of GAS in Japan.

Induction of interferon-inducible protein-10 and monokine induced by interferon-γ from human endothelial cells infected with Influenza A virus

Summary.Primary human umbilical vein endothelial cells (HUVECs) were infected with Influenza virus A/Aichi/2/68 (H3N2) in order to determine the role of endothelial cells in mediating inflammation induced upon virus infection. Structural proteins of the virus and mRNA of the M2 protein were detected in the infected cells, indicating that virus infection had occurred in HUVECs. The Influenza A virus-infected HUVECs showed elevated levels of gene expression of interferon (IFN)-inducible protein (IP)-10 and monokine induced by IFN-γ (Mig), while heat-, formalin- and diethyl ether-inactivated viruses did not enhance the IP-10 and Mig gene expression. The results thus indicate that infection of live Influenza A virus is responsible for elevation of IP-10 and Mig gene expression. The elevation of IP-10 and Mig gene expression in infected HUVECs was not accompanied by the elevation of IFN-γ gene expression, indicating that the elevation of IP-10 and Mig gene expression was independent of the IFN-γ pathway.

Unusual Presentation of Measles Giant Cell Pneumonia in a Patient with Acquired Immunodeficiency Syndrome

The typical clinical presentation of measles in a normal immunocompetent host includes cough, coryza, conjunctivitis, Kopliks spots, and rash. However, in an immunocompromised host, measles may have an atypical clinical presentation and may be commonly associated with severe pneumonia or encephalitis. We report a fatal case of measles pneumonia without any clinical features that suggest measles in a patient with acquired immunodeficiency syndrome.

Protein-Losing Cytomegalovirus Gastritis in a Patient with Stevens-Johnson Syndrome

We present a case of protein-losing cytomegalovirus gastritis in a previously immunocompetent 14-year-old Japanese girl that occurred during treatment of drug (zonisamide)-induced Stevens-Johnson syndrome with hepatic failure. Her hepatic failure and symptoms of Stevens-Johnson syndrome were successfully treated with intravenous prednisolone and infusion of fresh-frozen plasma or albumin, as the occasion demanded. However, during the course of treatment, she complained of severe epigastralgia together with hypoproteinemia, and cytomegalovirus gastritis was found by endoscopic and histological examinations. The possible mechanism by which cytomegalovirus gastritis occurred in the present case and effective diagnostic procedures are discussed.

Therapeutic efficacy of azithromycin, clarithromycin, minocycline and tosufloxacin against macrolide-resistant and macrolide-sensitive Mycoplasma pneumoniae pneumonia in pediatric patients

Objective To clarify therapeutic effects of azithromycin, clarithromycin, minocycline and tosufloxacin against macrolide-resistant Mycoplasma pneumoniae (MRMP) pneumonia and against macrolide-sensitive Mycoplasma pneumoniae (MSMP) pneumonia in pediatric patients. Methods A prospective, multicenter observational study was conducted from July 2013 to August 2015. The therapeutic effects of azithromycin, clarithromycin, minocycline and tosufloxacin were evaluated in 59 patients with pneumonia caused by MRMP and in 50 patients with pneumonia caused by MSMP. In vitro activities of antimicrobial agents against isolates of Mycoplasma pneumoniae were also measured. Results Mean durations of fever following commencement of treatment in patients infected with MRMP and MSMP were 5.2 and 1.9 days, respectively (log-rank test, P < 0.0001). Among patients infected with MRMP, mean durations of fever were 4.6, 5.5, 1.0 and 7.5 days for patients treated with azithromycin, clarithromycin, minocycline and tosufloxacin, respectively (log-rank test, P < 0.0001). Among patients infected with MSMP, mean durations of fever were 2.5, 1.7, 0.9 and 4.3 days for patients treated with azithromycin, clarithromycin, minocycline and tosufloxacin, respectively (log-rank test, P = 0.0162). The MIC90s of azithromycin and clarithromycin among the 27 isolates of MRMP were 64 and 256 μg/ml, respectively, and those among the 23 isolates of MSMP were <0.000125 and 0.001 μg/ml, respectively. The MIC90s of minocycline and tosufloxacin among the 27 isolates of MRMP were 1.0 and 0.25 μg/ml, respectively, and those among the 23 isolates of MSMP were 1.0 and 0.5 μg/ml, respectively. Conclusion Both minocycline and tosufloxacin showed good in vitro activities against MRMP. Minocycline, but not tosufloxacin, shortened the duration of fever in pediatric patients infected with MRMP compared to the duration of fever in patients treated with macrolides.