Details of a Researcher - Shinjo, Masayoshi

Papers - Shinjo, Masayoshi

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Safety and efficacy of linezolid in 16 infants and children in Japan

Shinjoh Masayoshi, Iketani Osamu, Watanabe Kota, Shimojima Naoki, Kudo Mikihiko, Yamagishi Hiroyuki, Shimada Hiroyuki, Sugita Kayoko, Takahashi Takao, Mori Takehiko, Hasegawa Naoki, Iwata Satoshi

Journal of Infection and Chemotherapy 18 ( 4 ) 591 - 596 2012.08

ISSN 1341-321X

Linezolid, an oxazolidinone antibiotic, exhibits a broad spectrum of activity against Gram-positive bacteria. It hasbeen licensed for adult use in Japan since 2006 for MRSA infections, and has also been used off-label for pediatric patients.At our university hospital, a total of 16 infants and children (including one non-Japanese Asian) were administered linezolidowing to infection with multidrug-resistant Gram-positive bacteria, after consent had been provided. All patients had severeunderlying diseases or indications for surgery. Eighty-eight percent of the causal microorganisms were methicillin-resistantStaphylococcus aureus (MRSA) or methicillin-resistant coagulase-negative Staphylococcus and all were sensitive to linezolid.Linezolid was administered because the antecedent anti-MRSA medications were ineffective or contraindicated, orintravenous-to-oral switch therapy was requested owing to cardiac or orthopedic surgical-site infections. The median durationof administration was 13 days (range 3-31 days). The overall efficacy was 91 % (10/11) in those for whom efficacy could beevaluated. Only two patients (both teen-aged) encountered linezolid-related adverse effects (13 %, 2/16). One patient showedelevation of liver enzymes (aspartate aminotransferase [AST] and alanine aminotransferase [ALT]), requiring thatadministration be withdrawn, but enzyme levels returned to normal after the patient had been switched to vancomycin. Theother patient showed transiently decreased platelet counts. Linezolid is considered generally safe and effective for childrenin Japan, especially for those who cannot use other anti-MRSA medications or those who require oral antibiotics forinfections with multidrug-resistant Gram-positive bacteria. © 2012 Japanese Society of Chemotherapy and The JapaneseAssociation for Infectious Diseases.

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Influenza-related mortality trends in japanese and american seniors

Charu Vivek, Viboud Cécile, Simonsen Lone, Sturm-Ramirez Katharine, Shinjoh Masayoshi, Chowell Gerardo, Miller Mark, Sugaya Norio

PLoS ONE 6 ( 11 ) 2011.11

Background: The historical Japanese influenza vaccination program targeted at schoolchildren provides a unique opportunity to evaluate the indirect benefits of vaccinating high-transmitter groups to mitigate disease burden among seniors. Here we characterize the indirect mortality benefits of vaccinating schoolchildren based on data from Japan and the US. Methods: We compared age-specific influenza-related excess mortality rates in Japanese seniors aged ≥65 years during the schoolchildren vaccination program (1978-1994) and after the program was discontinued (1995-2006). Indirect vaccine benefits were adjusted for demographic changes, socioeconomics and dominant influenza subtype; US mortality data were used as a control. Results: We estimate that the schoolchildren vaccination program conferred a 36% adjusted mortality reduction among Japanese seniors (95%CI: 17-51%), corresponding to ~1,000 senior deaths averted by vaccination annually (95%CI: 400-1,800). In contrast, influenza-related mortality did not change among US seniors, despite increasing vaccine coverage in this population. Conclusions: The Japanese schoolchildren vaccination program was associated with substantial indirect mortality benefits in seniors.

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Very low pandemic influenza A (H1N1) 2009 mortality associated with early neuraminidase inhibitor treatment in Japan

Sugaya Norio, Shinjoh Masayoshi, Mitamura Keiko, Takahashi Takao

Journal of Infection 63 ( 4 ) 288 - 294 2011.10

ISSN 0163-4453

Objective: There were many cases of pandemic influenza A (H1N1) 2009 (H1N1/09) in Japan during the 2009-2010 epidemic. They accounted for 16% of the total population (20.7 million/128 million), and 59% of the patients were children 15 years of age and under (12.2 million/20.7million). However, there were only 38 paediatric deaths. We analyzed the clinical manifestations and treatment of children hospitalized because of H1N1/09 infection in order to clarify the association between treatment with neuraminidase inhibitors and the low mortality rate. Methods: A retrospective chart review was performed on a total of 1000 paediatric inpatients. Results: The causes of the hospitalizations were respiratory complications in 651 cases (65.1%), neurological complications in 255 cases (25.5%) and other complications in 94 cases. Neuraminidase inhibitors, primarily oseltamivir, had been used to treat 984 (98.4%) of the 1000 patients, and in 88.9% of the patients, treatment with neuraminidase inhibitors was initiated within 48 h after the onset of illness. Only 12 (1.2%) of the 1000 patients underwent mechanical ventilation, and one patient died of H1N1/09 infection. Conclusions: Although a high proportion of the patients in this study had severe respiratory complications, the case fatality rate was only 0.1%. The low mortality rate of children due to the H1N1/09 epidemic in Japan was probably attributable to the universal implementation of early treatment with neuraminidase inhibitors. © 2011 The British Infection Association.

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Klebsiella oxytoca-positive, penicillin-associated hemorrhagic enterocolitis in children

Shinjoh Masayoshi, Iwata Satoshi, Takahashi Takao

Pediatrics International 52 ( 1 ) 132 - 153 2010.02

ISSN 1328-8067

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Varicella zoster exposure on paediatric wards between 2000 and 2007

Shinjoh M., Takahashi T.

Journal of Hospital Infection 72 ( 2 ) 163 - 168 2009.06

ISSN 0195-6701

Varicella zoster virus is highly contagious and can cause serious complications in immunocompromised patients. To prevent people exposed to the virus from developing secondary varicella we have used oral aciclovir as post-exposure prophylaxis (PEP) since 2000. Between 2000 and 2007, there were 11 unexpected occurrences of varicella and 11 unexpected occurrences of zoster in our paediatric wards. There were 174 contacts, 131 exposed to varicella and 43 exposed to zoster. A total of 163 (94%) received PEP and 11 (6%) did not. The rates of secondary infection among contacts given prophylaxis with aciclovir only were 2.1% (3/141) for all contacts and 1.3% (1/76) for immunocompetent contacts. The rate of secondary infection among contacts not given PEP was significantly higher (18%, 2/11) (P < 0.05). No adverse events due to PEP were reported. We conclude that oral aciclovir PEP following exposure to VZV on paediatric wards is both safe and effective. © 2009 The Hospital Infection Society.

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Effective and safe immunizations with live-attenuated vaccines for children after living donor liver transplantation

Shinjoh Masayoshi, Miyairi Isao, Hoshino Ken, Takahashi Takao, Nakayama Tetsuo

Vaccine 26 ( 52 ) 6859 - 6863 2008.12

ISSN 0264-410X

Immunizations using live-attenuated vaccines are not recommended for post-liver transplant children due to its theoretical risks. However, they will encounter vaccine-preventable viral diseases upon returning to real-life situations. We performed a total of 70 immunizations with four individual live-attenuated vaccines to 18 pediatric post-living donor liver transplant (LDLT) recipients who fulfilled a clinical criteria including humoral and cell-mediated immunity. The seroconversion rates at the first dose for measles (strain AIK-C), rubella (strain TO-336), varicella (strain Oka), and mumps (strains Hoshino) were 100% (15/15), 100% (15/15), 82% (9/11), and 82% (9/11), respectively. During observed period (-5 years 11 months), a few cases with waning immunity (antibodies were once produced but the levels fell over time) were seen except after rubella immunization. Clinical diseases after seroconversion or definite serious adverse effects due to immunization were not observed. Immunizations using selected live-attenuated vaccines were safe and effective for post-LDLT children who were not severely immunosuppressed. © 2008 Elsevier Ltd. All rights reserved.

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Cryptococcal meningitis in an immunocompetent child

Shinjoh Masayoshi, Miyairi Isao, Sakurai Michiko, Takahashi Miki, Ariyasu Daisuke, Nakayama Tetsuo, Tokumura Mitsuaki, Yamashita Ryoko, Sunakawa Keisuke, Takahashi Takao

European Journal of Pediatrics 164 ( 9 ) 596 - 597 2005.08

ISSN 0340-6199

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Effect of post-exposure prophylaxis with oseltamivir for those in contacts with influenza patients in pediatric wards

Shinjoh Masayoshi, Sato Seiji, Sugaya Norio, Mitamura Keiko, Takeuchi Yoshinao, Kosaki Kenjiro, Takahashi Takao

Kansenshogaku zasshi. The Journal of the Japanese Association for Infectious Diseases 78 ( 3 ) 262 - 269 2004

ISSN 0387-5911

During the influenza season, outbreaks of influenza may occur in the pediatric wards due to spread from the patients hospitalized with influenza, or from those hospitalized during the latency period and develop influenza afterwards. Post-exposure prophylaxis with neuraminidase inhibitors has been reported to be effective in preventing outbreaks among household members and nursing home residents. However, for nosocomial spread, its effectiveness and possible adverse effects are to be determined. During the 2002/2003 influenza season, we experienced a total of 3 nosocomial outbreaks of influenza in the pediatric wards in two hospitals in the Kanto district, Japan. Since the number of contacts who developed influenza had been increasing despite the isolation precaution implemented, post-exposure prophylaxis with oseltamivir (2 mg/kg/dose, maximum 75 mg/dose, once a day for 7-10 days) was implemented with a permission from the parents to terminate the outbreaks. In the outbreaks (one with influenza A, two with influenza B), a total of 29 inpatients had contact with influenza patients: among those 29, 13 were given post-exposure prophylaxis, 16 were not. Out of 16 patients who did not receive post-exposure prophylaxis, 11 (69%) developed influenza: out of 13 with post-exposure prophylaxis, none developed influenza. Those patients who developed influenza were given oseltamivir (2 mg/kg/dose, maximum 75 mg/dose, twice a day for 5 days) and accommodated in a private room or a room with other patients with influenza of the same type. No significant adverse effects due to oseltamivir were observed among those who were enrolled in this study.

Evaluation of an immunochromatography test using enzyme immunoassay for rapid detection of influenza A and B viruses

Mitamura Keiko, Yamazaki Masahiko, Ichikawa Masataka, Kimura Kazuhiro, Kawakami Chiharu, Shimizu Hideaki, Watanabe Sumi, Imai Mitsunobu, Shinjo Masayoshi, Takeuchi Yoshinao, Sugaya Norio

Kansenshogaku zasshi. The Journal of the Japanese Association for Infectious Diseases 78 ( 7 ) 597 - 603 2004

ISSN 0387-5911

We evaluated the performance of an improved version of Espline Influenza A & B-N (Fujirebio Inc., Japan), an immunochromatography test using enzyme immunoassay for rapid diagnosis of influenza A and B. The test produced positive results for four strains of influenza viruses and thirty-one influenza viral antigens and negative results for all of thirty strains of other respiratory viruses that were tested. The detection limit of this test was 5.8 x 10(2) to 5.8 x 10(3) pfu/assay, which is more sensitive than the old version of Espline. Furthermore, 715 respiratory specimens collected from the patients (children, 79.4%; adults, 18.5%; unknown, 2.1%) with influenza-like illnesses during the 2002/2003 influenza season in Japan were tested as part of a clinical evaluation of this test. The relative performance of this test compared to cell culture and nested RT-PCR results were examined. In the cell cultures, influenza viruses were detected in 488 of the 715 specimens (overall, 68.3%; AH3, 41.7%; B, 26.4%; AH3 and B, 0.1%). For influenza A, the sensitivity of this test was 95.4% (125/131) for nasal aspirates, 96.8% (92/95) for nasal swabs, and 85.1% (63/74) for throat swabs. For influenza B, the sensitivity of this test was 91.2% (52/57) for nasal aspirates, 88.1% (59/67) for nasal swabs, and 71.6% (48/67) for throat swabs. The new test exhibited a remarkably higher sensitivity to influenza A in throat swabs than the old version of Espline. Only two false positive results were obtained out of a total of 223 virus negative specimens; the specificity of the test was 100% (88/88) for nasal aspirates, 97.6% (81/83) for nasal swabs, and 100% (52/52) for throat swabs. We conclude that the new Espline Influenza A&B-N rapid diagnostic test is easy to use and has a high sensitivity and specificity, especially for influenza A.

Perspectives on the characteristics and achievements of recent surveillance of influenza activity in Japan

Nerome R., Nerome K., Tanabe N., Lindstrom S. E., Shinjo M., Taniguchi S., Kasai K.

Vaccine 20 ( SUPPL. 2 ) 2002.05

ISSN 0264-410X

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Effectiveness of oseltamivir treatment against influenza type A and type B infection in children

Mitamura Keiko, Sugaya Norio, Nirasawa Mari, Shinjoh Masayoshi, Takeuchi Yoshinao

Kansenshogaku zasshi. The Journal of the Japanese Association for Infectious Diseases 76 ( 11 ) 946 - 952 2002

ISSN 0387-5911

We investigated the effectiveness of oseltamivir treatment against influenza virus infection in children. We treated 131 patients (mean age, 5.8 +/- 3.6 years) with oseltamivir (4 mg/kg/day for 5 days) during the 2001-2002 epidemic. All of the patients had been diagnosed with influenza using a rapid diagnosis kit. When treatment was initiated within 48 hours of the onset of fever, 44% of the patients became afebrile (< 37.5 degrees C) within one day, and 86% of them recovered within two days. The average duration of fever after the initiation of oseltamivir treatment was 1.7 days. Oseltamivir was equally effective against both influenza type A and type B. No differences in the effectiveness of oseltamivir treatment were observed between young children (< 4 years of age) and school-aged children (> 6 years of age). No obvious side effects were observed.

Cytomegalovirus retinitis during immunotherapy for common variable immunodeficiency [4]

Ishikawa K., Ando Y., Narita M., Shinjoh M., Iwasaki T.

Journal of Infection 44 ( 1 ) 55 - 56 2002

ISSN 0163-4453

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Prophylaxis and treatment of influenza encephalitis in an experimental mouse model

Shinjoh Masayoshi, Yoshikawa Takashi, Li Yixing, Shiraishi Kyoko, Ueki Hideaki, Nerome Kuniaki

Journal of Medical Virology 67 ( 3 ) 406 - 417 2002

ISSN 0146-6615

A mouse model study using mouse brain-adapted influenza A virus was performed to establish the prophylaxis and treatment of influenza encephalitis and encephalopathy. All mice died after intranasal inoculation of the brain-adapted influenza A virus (H7N3), and the pathological findings indicated the presence of significant encephalitis. Viral antigen was also detected in the brain, both pathologically and virologically. By contrast, infected mice immunized with inactivated vaccine of the same strain did not lose weight, which is an indicator of the overall condition of the mice, and all of them survived. Similarly, antiserum treatment in the early period (0-1 day post-infection) resulted in 100% survival, and no pathological findings were observed in the brain. However, mice treated with antiserum 3 days post-infection showed encephalitis with viral antigens in both glial cells and neurocytes. Although amantadine treatment for 4 days delayed weight loss, it did not prevent death from encephalitis. These results show vaccination and early antiserum treatment to be highly effective, whereas 4-day treatment of amantadine was not very effective in treating or preventing influenza encephalitis. The life-prolonging effect of amantadine, however, suggests that use of amantadine together with other treatments may inhibit the progression of encephalitis. © 2002 Wiley-Liss, Inc.

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Diagnosis and Treatment of Influenza Associated Encephalopathy in Children

Shinjoh Masayoshi

Japanese Journal of Chest Diseases 60 ( 11 ) 1023 - 1024 2001.11

ISSN 0385-3667

Genetic analysis of an influenza B virus isolated from a patient with encephalopathy in Japan

Shiraishi Kyoko, Lindstrom Stephen E., Saito Takehiko, Shinjoh Masayoshi, Nerome Reiko, Funatsumaru Sadayuki, Nerome Kuniaki

Journal of Medical Virology 65 ( 3 ) 590 - 597 2001

ISSN 0146-6615

An influenza B virus, B/Saga/S172/99 (SAG99), was isolated from the nasopharynx of a patient with encephalopathy/encephalitis in Japan in 1999. To clarify the molecular characteristics of this virus, detailed analysis of the gene segments coding for the hemagglutinin (HA), neuraminidase (NA), nucleoprotein (NP), matrix protein (M) and non-structural protein (NS) was undertaken. All five genes of SAG99 showed high nucleotide and predicted amino acid similarities with those of recent non-encephalopathic strains isolated in the same epidemic season. Subsequent phylogenetic analysis revealed that all five gene segments of SAG99 analyzed in the present study were most similar to those of the recent Yamagata/16/88-like viruses. The hemagglutinin and neuraminidase proteins of SAG99 were each distinguished from those of recent epidemic strains by one characteristic amino acid substitution. These substitutions were not found in the previously reported encephalopathy/encephalitis-derived influenza B viruses, and we could not find any common characteristic amino acid changes in SAG99 and these viruses. Similarly, among the internal proteins studied, only the M2 protein of SAG99 was found to contain a single novel amino acid change when compared with other recent isolates. Thus, it was apparent that SAG99 contained very few amino acid differences when compared with other epidemic viruses. The association of recent B/Yamagata/16/88-like viruses with encephalitis/encephalopathy observed in the present study and previously suggest that these viruses may have a higher potential for causing neurological complications in certain individuals. © 2001 Wiley-Liss, Inc.

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In vitro growth profiles of respiratory syncytial virus in the presence of influenza virus

Shinjoh M., Omoe K., Saito N., Matsuo N., Nerome K.

Acta Virologica 44 ( 2 ) 91 - 97 2000

ISSN 0001-723X

To elucidate epidemiological interference between respiratory syncytial (RSV) and influenza viruses, the influence of influenza A (H1N1) virus on the growth of RSV was examined. Although RSV grew in MDCK cells, coinfection with influenza A virus led to a reduction of progeny RSV. The degree of growth interference depended on the time of infection with influenza A virus post infection (p.i.) with RSV. In fact, infection with influenza A virus 12 hrs p.i. with RSV did not influence growth of the latter virus. On the contrary, growth suppression of influenza A virus by RSV was observed when the coinfection began at the later stages of RSV infection. Suppression of the growth of RSV by influenza A infection was further demonstrated at the level of viral protein synthesis. An indirect immunofluorescence (IF) test revealed that a large proportion of infected cells synthesized both RSV and influenza A Virus antigens. Scanning electron microscopic (SEM) examination demonstrated that influenza A and RSV virions possessing surface antigens specific for each virus were selectively released from dually infected cells. In the present study, we proved for the first time that the growth of RSV is blocked by competitive infection with influenza A Virus in a susceptible cell population, competitive protein synthesis and selective budding of RSV and influenza Viruses from the same infected cells.

Phylogenetic analysis of the three polymerase genes (PB1, PB2 and PA) of influenza B virus

Hiromoto Yasuaki, Saito Takehiko, Lindstrom Stephen E., Li Yixing, Nerome Reiko, Sugita Shigeo, Shinjoh Masayoshi, Nerome Kuniaki

Journal of General Virology 81 ( 4 ) 929 - 937 2000

ISSN 0022-1317

Phylogenetic patterns of the three polymerase (PB2, PB1 and PA) genes of a total of 20 influenza B viruses isolated during a 58 year period, 1940-1998, were analysed in detail in a parallel manner. All three polymerase genes consistently showed evolutionary divergence into two major distinct lineages and their amino acid profiles demonstrated conserved lineage-specific substitutions. Dendrogram topologies of the PB2 and PB1 genes were very similar and contrasted with that of the PA gene. It was of particular interest to reveal that even though the PA gene evolved into two major lineages, that of three recent Asian Victoria/1/87-like strains formed a branch cluster located in the same lineage as that of recent Yamagata/16/88-like isolates. Differences in the phylogenetic pathways of three polymerase genes were not only a reflection of genetic reassortment between co-circulating influenza B viruses, but also an indication that the polymerase genes were not co-evolving as a unit. As a result, comparison of the phylogenetic patterns of the three polymerase genes with previously determined patterns of the HA, NP, M and NS genes of is viruses defined the existence of eight distinct genome constellations. Also, similar phylogenetic profiles among the PA, NP and M genes, as well as between the PB2 and PB1 genes, were observed, suggesting possible functional interactions among these proteins. Completion of evolutionary analysis of the six internal genes and the HA gene of influenza B viruses revealed frequent genetic reassortment among co-circulating variable strains and suggested co-dependent evolution of genes.

Influenza A-associated encephalopathy with bilateral thalamic necrosis in Japan

Shinjoh M., Bamba M., Jozaki K., Takahashi E., Koinuma G., Sugaya N.

Clinical Infectious Diseases 31 ( 2 ) 611 - 613 2000

ISSN 1058-4838

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Acute encephalitis and encephalopathy associated with influenza virus

Shinjoh Masayoshi, Nerome Kuniaki

Brain and Nerve 51 ( 10 ) 851 - 860 1999

ISSN 0006-8969

Contraction of vascular smooth muscle by Na⁺ channel activators

Shinjoh M., Nakaki T., Otsuka Y., Sasakawa N., Kato R.

Japanese Journal of Pharmacology 58 ( SUPPL. 2 ) 1992

ISSN 0021-5198

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