Displaying all 15 publications

Abstract:
Sort:
  1. Morita K, Igarashi A
    J Gen Virol, 1984 Nov;65 ( Pt 11):1899-908.
    PMID: 6094708
    Eighteen strains of Getah virus isolated from mosquitoes, swine and horses in Japan (1956 to 1981), and one strain isolated in Malaysia (1955), were analysed by RNase T1-resistant oligonucleotide fingerprinting. All fingerprints showed a poly(A) tract. The fingerprint pattern of the Malaysian strain was quite different from those of the Japanese strains. Although most of the recent Japanese isolates shared many large oligonucleotide spots in common, the patterns were not identical even among the strains obtained in one locality in the same year. These results suggest that the Getah virus genome undergoes mutation rather frequently. However, there is a tendency for the isolates of the same year to show greater similarity. The fingerprint patterns of certain host-dependent temperature-sensitive (ts) mutants differed from that of the parental strain. Also, there were some differences in large oligonucleotide spots between strain JaNAr12380M isolated in suckling mouse brain (SMB) and strain JaNAr12380A isolated in C6/36 cells, despite the fact that both strains were derived from the same wild mosquito homogenate. In addition, many host-dependent ts mutants were present in strain JaNAr12380A, whereas no such mutants were observed in strain JaNAr12380M. It is concluded that there is considerable variation in the strains of Getah virus infecting mosquitoes in the wild, and also that the variants or mutants present in mosquitoes might be subject to selection during viral multiplication in the mammalian host.
  2. Zin K, Morita K, Igarashi A
    Microbiol. Immunol., 1995;39(8):581-90.
    PMID: 7494497
    We determined the 240-nucleotide sequences of the E/NS1 gene junction of four dengue-2 viruses by the primer extension dideoxy chain termination method. These viruses were isolated from dengue patients with different clinical severities in Nakhon Phanom, Northeastern Thailand in 1993. The results were compared with the 52 published dengue-2 sequences of the same gene region. Sequence divergence of four new isolates varied from 4.17% to 5.42% compared with dengue-2 prototype New Guinea C strain whereas it varied from 5.42% to 6.67% and from 6.67% to 7.09% when compared with Jamaica 1409 strain and PR159/S1 strain, respectively. All nucleotide substitutions were found at the 3rd position of the codons which were silent mutations. All 56 isolates studied were classified into five genotypic groups by constructing the dendrogram. The results indicated that four new isolates from Northeastern Thailand belong to genotype II of dengue virus serotype 2, and were most closely related to prototype New Guinea C strain. We also observed the variation in nucleotide and amino acid sequences among clusters of isolates (Thailand-1980, Malaysia-1989 and Thailand-1993) which were obtained from the dengue patients with different clinical severities. The significance of these genetic differences have been discussed in terms of the possible correlation between genetic variability and virulence.
  3. Srivastava AK, Igarashi A
    Acta Virol., 1986 Mar;30(2):126-30.
    PMID: 2873729
    Purified preparations of Getah virus strains have been analysed by sodium-dodecyl-sulphate polyacrylamide gel electrophoresis (SDS-PAGE) to reveal their structural proteins. Two envelope proteins (E1 and E2) and core protein (C) were found with the prototype AMM2021 strain both under reducing and nonreducing conditions, while separation of E1 and E2 was observed only under nonreducing conditions for 3 strains isolated in Japan. Limited digestion by Staphylococcus aureus V8 protease revealed difference in the peptide patterns of E1 between AMM2021 and Japanese isolates. Mobility of E1 and E2 was slower for the virus grown in BHK21 cells compared with the virus grown in Aedes albopictus cells, indicating host-controlled modification on the envelope glycoproteins.
  4. Kobayashi N, Thayan R, Sugimoto C, Oda K, Saat Z, Vijayamalar B, et al.
    Am J Trop Med Hyg, 1999 Jun;60(6):904-9.
    PMID: 10403318
    To characterize the dengue epidemic that recently occurred in Malaysia, we sequenced cDNAs from nine 1993-1994 dengue virus type-3 (DEN-3) isolates in Malaysia (DEN-3 was the most common type in Malaysia during this period). Nucleic acid sequences (720 nucleotides in length) from the nine isolates, encompassing the precursor of membrane protein (preM) and membrane (M) protein genes and part of the envelope (E) protein gene were aligned with various reference DEN-3 sequences to generate a neighbor-joining phylogenetic tree. According to the constructed tree, the nine Malaysian isolates were grouped into subtype II, which comprises Thai isolates from 1962 to 1987. Five earlier DEN-3 virus Malaysian isolates from 1974 to 1981 belonged to subtype I. The present data indicate that the recent dengue epidemic in Malaysia was due to the introduction of DEN-3 viruses previously endemic to Thailand.
  5. Thayan R, Morita K, Vijayamalar B, Zainah S, Chew TK, Oda K, et al.
    PMID: 9444025
    The aim of this study was to determine whether mutations could occur in the dengue virus genome following three subpassages of the virus in a mosquito cell line. This was done because sources of virus isolates used for sequencing studies are usually maintained in cell lines rather than in patients' sera. Therefore it must be assured that no mutation occurred during the passaging. For this purpose, sequencing was carried out using the polymerase chain reaction (PCR) products of the envelope/non-structural protein 1 junction region (280 nucleotides) of dengue type 3 virus. Sequence data were compared between the virus from a patient's serum against the virus subpassaged three times in the C6/36 cell line. We found that the sequence data of the virus from serum was identical to the virus that was subpassaged three times in C6/36 cell line.
  6. Thayan R, Vijayamalar B, Zainah S, Chew TK, Morita K, Sinniah M, et al.
    PMID: 9139373
    This study describes the use of polymerase chain reaction as a diagnostic tool for detecting and typing of dengue virus. PCR was compared against virus isolation. First RT-PCR was done using dengue consensus primers after which positive samples were subjected to RT-PCR using type-specific primers. This study shows that the local strains of the dengue virus could be detected using the chosen primers. Furthermore, RT-PCR was found to be more sensitive than virus isolation in identifying the dengue positive samples.
  7. Vythilingam I, Oda K, Chew TK, Mahadevan S, Vijayamalar B, Morita K, et al.
    J Am Mosq Control Assoc, 1995 Mar;11(1):94-8.
    PMID: 7616198
    Detection and isolation of Japanese encephalitis (JE) virus were attempted from female mosquitoes collected in Kampong Pasir Panjang, Sabak Bernam, Selangor, from May to November 1992. A total of 7,400 mosquitoes consisting of 12 species in 148 pools were processed and inoculated into Aedes albopictus clone C6/36 cell cultures. Of these, 26 pools showed the presence of viral antigens in the infected C6/36 cells by specific immunoperoxidase staining using an anti-JE virus polyclonal antibody. Presence of JE virus genome was confirmed in the infected culture fluid for 16 pools by using reverse transcriptase-polymerase chain reaction and JE virus-specific primers. Of these, 3 pools were from Culex tritaeniorhynchus, 4 from Culex vishnui, 3 from Culex bitaeniorhynchus, 2 from Culex sitiens, one from Aedes species, and 3 from Culex species. Isolation of JE virus from Cx. sitiens, Cx. bitaeniorhynchus, and Aedes sp. (Aedes butleri and Ae. albopictus) is reported for the first time in Malaysia.
  8. Müller M, Igarashi A, Hashiguchi K, Kappel M, Paolini F, Yoshisue H, et al.
    J Med Econ, 2022 1 25;25(1):220-229.
    PMID: 35072591 DOI: 10.1080/13696998.2022.2033051
    AIMS: Japanese cedar pollinosis (JCP) is a form of seasonal allergic rhinitis that affects 38.8% of the Japanese population. Particularly severe and most severe symptoms among JCP patients can lead to impairments of paid work productivity and unpaid work activities. Indeed, the current standard of care (SoC) is not always able to relieve these symptoms. Omalizumab, a novel JCP treatment recently approved in Japan, provides an effective add-on therapy to the SoC. This study estimates the effect of omalizumab on paid and unpaid work activities (i.e. its social impact) in patients with severe and most severe JCP symptoms in Japan.

    METHODS: The impact of omalizumab was estimated through a one-year static cohort model using the Work Productivity and Activity Impairment Allergy Specific (WPAI-AS) questionnaire derived from a clinical trial on omalizumab enrolling patients with severe and most severe JCP symptoms, which had been conducted in Japan. This effect was quantified using Japanese official statistics on employment and time use. The human capital approach and the proxy good approach were employed to monetize paid and unpaid work activities, respectively. A sensitivity analysis was implemented to account for modeling structural uncertainties.

    RESULTS: Our results show that the use of omalizumab might reduce the paid and unpaid work productivity losses due to severe and most severe JCP by nearly one-third. In the severe symptom period of three weeks, 36.6 million hours of lost paid and unpaid work hours could be avoided, which sums up to a monetized productivity loss of 728.3 million USD.

    CONCLUSIONS: Omalizumab could provide substantial benefits in terms of paid and unpaid work activities in patients with severe and most severe JCP. Our results also highlight the importance of considering unpaid work in estimating productivity costs due to poor health.

  9. Hasebe F, Parquet MC, Pandey BD, Mathenge EG, Morita K, Balasubramaniam V, et al.
    J Med Virol, 2002 Jul;67(3):370-4.
    PMID: 12116030
    A reverse transcription-polymerase chain reaction (RT-PCR) was developed for the detection of Chikungunya virus infection. Based on the nonstructural protein 1 (nsP1) and glycoprotein E1 (E1) genes of Chikungunya, two primer sets were designed. Total RNA were extracted from the cell culture fluid of Aedes albopictus C6/36 cells inoculated with the S27 prototype virus, isolated in Tanzania in 1953, and the Malaysian strains (MALh0198, MALh0298, and MALh0398), isolated in Malaysia in 1998. For both sets of RNA samples, the expected 354- and 294-base pair (bp) cDNA fragments were amplified effectively from the nsP1 and E1 genes, respectively. Phylogenetic analysis was conducted for the Malaysian strain and other virus strains isolated from different regions in the world endemic for Chikungunya, using partial E1 gene sequence data. The Malaysian strains isolated during the epidemics of 1998 fell into a cluster with other members of the Asian genotype.
  10. Tsuchie H, Oda K, Vythilingam I, Thayan R, Vijayamalar B, Sinniah M, et al.
    Jpn. J. Med. Sci. Biol., 1994 Apr;47(2):101-7.
    PMID: 7853748
    Two hundred and forty nucleotides from the pre-M gene region of 10 Japanese encephalitis (JE) virus strains isolated in Malaysia in 1992 were sequenced and compared with the other JE virus strains from different geographic areas in Asia. Our JE virus strains belong to the largest genotypic group that includes strains isolated in temperate regions such as Japan, China, and Taiwan. Our Malaysian JE virus strains differed in 32 nucleotides (13.3%) from WTP/70/22 strain isolated from Malaysia in 1970, which belonged to another distinct genotypic group.
  11. Vythilingam I, Oda K, Mahadevan S, Abdullah G, Thim CS, Hong CC, et al.
    J Med Entomol, 1997 May;34(3):257-62.
    PMID: 9151487
    A 2-yr study of Japanese encephalitis (JE) virus in Sepang District, Selangor, Malaysia, was carried out to identify the mosquito vectors and to determine their seasonal abundance, parity, and infection rates. In total, 81,889 mosquitoes belonging to 9 genera and > 50 species were identified from CDC trap collections augmented with dry ice during 1992 and 1993. Culex tritaeniorhynchus Giles and Culex gelidus Giles were the most abundant species, and both increased in numbers with increases in rainfall. Overall, 45 JE virus isolations were made from 7 species-Cx. tritaeniorhynchus (24), Cx. gelidus (12), Culex fuscocephala Theobald (2), Aedes butleri Theobald (4), Culex quinquefasciatus Say (1), Aedes lineatopennis Ludlow (1), and Aedes (Cancraedes) sp. (1). Based on elevated abundance and JE infection rates, Cx. tritaeniorhynchus appears to be the most important vector of JE virus in Sepang.
  12. Oda K, Igarashi A, Kheong CT, Hong CC, Vijayamalar B, Sinniah M, et al.
    PMID: 9185254
    Serum specimens were collected from 6 species of animals living in 9 states of Malaysia including Sabah, North Borneo in 1993. Antibodies against Japanese encephalitis (JE) virus in these sera were detected by means of hemagglutination-inhibition (HI) and neutralization (NT) tests. By HI test, 702 of 2,152 (32.6%) sera showed positive results. Higher positive rates were obtained by the NT test, in which 1,787 of 1,927 (92.7%) sera had antibodies against JE virus. All serum specimens with positive HI were confirmed as positive by the NT. Swine sera showed especially higher rates of antibody positive and higher antibody titers compared with other animals. These results suggest that JE infections are widely distributed among many animals of Malaysia, and pig is the most susceptible amplifier host for JE virus.
  13. Tsuchie H, Oda K, Vythilingam I, Thayan R, Vijayamalar B, Sinniah M, et al.
    Am J Trop Med Hyg, 1997 Feb;56(2):153-8.
    PMID: 9080873
    Two hundred forty nucleotides from the pre-membrane gene region of 12 Japanese encephalitis virus (JEV) strains isolated from three different regions of Malaysia from 1993 to 1994 were sequenced and compared with each other and with the JEV strains from different geographic areas in Asia. These 12 Malaysian isolates were classified into two genotypes. The four JEV strains isolated from Sarawak in 1994 and the four JEV strains isolated from Sepang, Selangor in 1993 were classified into one genotype that included earlier isolated strains from Malaysia (JE-827 from Sarawak in 1968 and WTP/70/22 from Kuala Lumpur in 1970). The four JEV strains from Ipoh, Perak in 1994 were classified into another genotype that included JEV strains isolated from northern Thailand and Cambodia. In an earlier report, 10 JEV strains from Sabak Bernam, Selangor in 1992 were classified into the largest genotype that included strains isolated in temperate regions such as Japan, China, and Taiwan. The data indicate that at least three genotypes of JEV have been circulating in Malaysia.
  14. Lam SK, Fong MY, Chungue E, Doraisingham S, Igarashi A, Khin MA, et al.
    Clin Diagn Virol, 1996 Nov;7(2):93-8.
    PMID: 9137865 DOI: 10.1016/S0928-0197(96)00257-7
    The traditional methods used in the diagnosis of dengue infection do not lend themselves to field application. As such, clinical specimens have to be sent to a central laboratory for processing which invariably leads to delay. This affects patient management and disease control. The development of the dengue IgM dot enzyme immunoassay has opened up the possibility of carrying out the test in peripheral health settings.
  15. Yang Z, Purba FD, Shafie AA, Igarashi A, Wong EL, Lam H, et al.
    Qual Life Res, 2022 Feb 18.
    PMID: 35181827 DOI: 10.1007/s11136-021-03075-x
    INTRODUCTION: Many countries have established their own EQ-5D value sets proceeding on the basis that health preferences differ among countries/populations. So far, published studies focused on comparing value set using TTO data. This study aims to compare the health preferences among 11 Asian populations using the DCE data collected in their EQ-5D-5L valuation studies.

    METHODS: In the EQ-VT protocol, 196 pairs of EQ-5D-5L health states were valued by a general population sample using DCE method for all studies. DCE data were obtained from the study PI. To understand how the health preferences are different/similar with each other, the following analyses were done: (1) the statistical difference between the coefficients; (2) the relative importance of the five EQ-5D dimensions; (3) the relative importance of the response levels.

    RESULTS: The number of statistically differed coefficients between two studies ranged from 2 to 16 (mean: 9.3), out of 20 main effects coefficients. For the relative importance, there is not a universal preference pattern that fits all studies, but with some common characteristics, e.g. mobility is considered the most important; the relative importance of levels are approximately 20% for level 2, 30% for level 3, 70% for level 4 for all studies.

    DISCUSSION: Following a standardized study protocol, there are still considerable differences in the modeling and relative importance results in the EQ-5D-5L DCE data among 11 Asian studies. These findings advocate the use of local value set for calculating health state utility.

Related Terms
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links