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The clinical effectiveness of four neuraminidase inhibitors (NAIs) (oseltamivir, zanamivir, laninamivir, and peramivir) for children aged 0 months to 18 years with influenza A and B were investigated in the 2014-2015 to 2016-2017 influenza seasons in Japan. A total of 1207 patients (747 with influenza A and 460 with influenza B) were enrolled. The Cox proportional-hazards model using all of the patients showed that the duration of fever after administration of the first dose of the NAI was shorter in older patients (hazard ratio = 1.06 per 1 year of age, p < 0.001) and that the duration of fever after administration of the first dose of the NAI was shorter in patients with influenza A infection than in patients with influenza B infection (hazard ratio = 2.21, p < 0.001). A logistic regression model showed that the number of biphasic fever episodes was 2.99-times greater for influenza B-infected patients than for influenza A-infected patients (p < 0.001). The number of biphasic fever episodes in influenza A-or B-infected patients aged 0-4 years was 2.89-times greater than that in patients aged 10-18 years (p = 0.010), and the number of episodes in influenza A-or B-infected patients aged 5-9 years was 2.13times greater than that in patients aged 10-18 years (p = 0.012).

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

Epstein-Barr virus (EBV) latent infection, and its associated oncogenic potential, is dependent on genome maintenance functions of EBV nuclear antigen 1 (EBNA-1), one of six EBNAs expressed from a common promoter (Wp and then Cp) upon infection of naive B cells. Subsequent host-mediated silencing, however, necessitates the expression of EBNA-1 from the EBNA-1-specific promoter Qp to ensure against genome loss during cell division, including EBV-associated malignancy. Here we addressed the mechanism by which EBNA-1 represses Qp through binding downstream of the transcription start site and the role of this autoregulatory function in EBV latency. Our results revealed that EBNA-1 does not inhibit transcription from Qp, as previously predicted, but acts post- or cotranscriptionally to block the processing of primary transcripts. This does not, however, require the RGG motifs responsible for strong but nonspecific RNA binding by EBNA-1. Within isogenic B-cell lines using either Cp/Wp or Qp, EBNA-1 occupancy of Qp is equivalent, suggesting that autoregulation occurs, albeit to different degrees, during full and restricted EBV latency programs. Finally, in cell lines using Cp or Wp for EBNA expression, unprocessed transcripts from Qp are detectable in the absence of corresponding mRNAs, providing further evidence that this novel mechanism of EBNA-1 action functions during latency. This posttranscriptional mechanism of regulation would provide an efficient means to monitor and regulate EBNA-1 expression from Qp, ensuring levels adequate for genome maintenance but, perhaps more importantly, below an immunogenic threshold above which latently infected cells may be at risk for elimination by EBNA-1-specific cytotoxic T cells.

Expression of different panels of latent gene transcripts is controlled by usage of three distinct Epstein-Barr virus (EBV) nuclear antigen (EBNA) promoters (Wp, Cp, and Qp). EBV-associated hemophagocytic syndrome, which is often a fatal disease and generally occurs after primary EBV infection, is characterized by monoclonal or oligoclonal proliferation of EBV-infected T cells. The latency pattern and EBNA promoter (Wp, Cp, and Qp) usage in EBV-infected cells from three patients with EBV-associated hemophagocytic syndrome were examined by reverse transcription-polymerase chain reaction (PCR). Three samples from the patients expressed EBER, EBNA1, EBNA2, latent membrane protein (LMP)1, and LMP2A transcripts. The transcripts of EBNA1 were initiated from not only Wp/Cp but also Qp. Lytic cycle Fp-initiated EBNA1 and EBV lytic gene BZLF1 transcripts were not detected. The methylation statuses of three EBNA promoters in three patients with EBV-associated hemophagocytic syndrome and in two patients with infectious mononucleosis were also analyzed using bisulfite PCR analysis. Wp was hypermethylated, and Qp was unmethylated in both diseases. Cp was highly methylated in EBV-associated hemophagocytic syndrome, however, whereas Cp was almost unmethylated in infectious mononucleosis. These results suggest that there may be distinct EBV-infected cell populations in EBV-associated hemophagocytic syndrome, which exhibit different patterns of EBV latent gene expression. The methylation status in Cp and phenotype of EBV-infected cells may be critical differences in EBV-associated hemophagocytic syndrome and infectious mononucleosis.

Chronic active Epstein–Barr virus infection (CAEBV) has been considered to be a non-neoplastic T-cell lymphoproliferative disease associated with Epstein–Barr virus (EBV) infection. In EBV-associated diseases, the cell phenotype-dependent differences in EBV latent gene expression may reflect the strategy of the virus in relation to latent infection. We previously reported that EBV latent gene expression was restricted; EBV nuclear antigen 1 (EBNA1) transcripts were consistently detected in all spleen samples from five CAEBV patients, but EBNA2 transcripts were detected in only one sample. EBV latent gene expression is controlled by distinct usage of three EBNA promoters (Cp, Wp and Qp). In this study, we examined the EBNA promoter usage by RT-PCR and the methylation status in the Cp and Wp regions using bisulfite PCR analysis in spleen samples from CAEBV patients. EBNA1 transcripts were unexpectedly initiated not from Qp but from Cp in all samples in spite of the restricted form of latency. Furthermore, while Cp was active, Cp was heavily methylated, indicating that CAEBV has unique EBV latent gene expression, EBNA promoter usage and EBNA promoter methylation status, in part due to unique splicing of Cp-initiated transcripts and an activation mechanism in hypermethylated Cp.

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.

A new human pneumovirus, provisionally designated human metapneumovirus, was discovered by Dutch researchers. We examined 142 serum samples from the general population aged from 1 month to 35 years in Japan for human metapneumovirus antibody by indirect immunofluorescence assays using human metapneumovirus-infected monkey kidney cells. The overall prevalence of human metapneumovirus infection was 72.5%. The seropositive rate was lowest in the age group of 6 months to 1 year and gradually increased with age. All of the children had been exposed to human metapneumovirus by the age of 10 years. The results show that human metapneumovirus is circulating in the Japanese population and is a ubiquitous virus acquired early in life.

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.

Chronic active Epstein–Barr virus (EBV) infection has been recognized as clonal non-neoplastic lymphoproliferative diseases. However, some reports of cases with a multiphenotypic expansion of EBV-infected lymphocytes give rise to questions of how EBV infects multiphenotypic lymphocytes and whether chronic active EBV infection is a truly monoclonal lymphoproliferative disease. We report two patients with chronic active EBV infection who showed expansion of multiphenotypic EBV-infected lymphocytes. EBV DNA was detected in CD4 + and CD8 + T cells and in B cells from pleural fluid of one patient and in T and B cells from a cervical lymph node of the other patient by polymerase chain reaction (PCR). Although real-time PCR showed that there were equally high loads of EBV genomes in CD4 + and CD8 + T cells from the pleural fluid, Southern blot hybridization with terminal repeats of the EBV genome showed a single band of the same molecular weight in three tissue samples from the patient. The results indicated biphenotypic expansions of CD4 + and CD8 + T cells infected with the same clone of EBV. Furthermore, bisulfite PCR analysis showed hypermethylated status in the Cp region in the two patients regardless of their cell populations. There has been a discrepancy between clonality and expansion of multiphenotypic EBV-infected lymphocytes. We speculate that lymphoid progenitor cells that have not differentiated into T and B cell progenitors are infected with EBV, resulting in clonal expansion of EBV-infected multiphenotypic cells.

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.

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 1 a of TTV might be more pathogenic than other genotypes in children.

The typical clinical presentation of measles in a normal immunocompetent host includes cough, coryza, conjunctivitis, Koplik's 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.