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Biomedical subjects

Norihisa Ishii

Publications and source records attributed to Norihisa Ishii.

At least 19 recordsLinked to original sources
PubMed2007

Muscle creatine kinase/SV40 hybrid promoter for muscle-targeted long-term transgene expression.

Gene therapy for congenital protein deficiencies requires lifelong expression of a deficient protein. Current gene therapy approaches preferentially employ the strong cytomegalovirus (CMV) promoter/enhancer or its derivative CAG promoter; however, these promoters provide only temporary transgene expression. To create a promoter that enables long-lasting expression in muscle, hybrid promoters were constructed by coupling the muscle creatine kinase (MCK) enhancer to various strong promoters for enhancement of tissue specificity and improved transcriptional activity. A hybrid promoter containing the MCK enhancer and the simian virus 40 promoter (MCK/SV40 promoter) yielded long-term (>6 months) expression of a human secretory alkaline phosphatase (huSEAP) reporter gene following electrotransfer of the plasmid into mice, whereas expression using a conventional CMV or CAG promoter faded away within a few weeks. To explore the mechanism behind the sustained expression obtained with the MCK/SV40 promoter, mice were immunized with a LacZ expression plasmid driven by MCK/SV40 or a conventional promoter. Minimal cellular and humoral responses to LacZ were observed in MCK/SV40 promoter-treated animals, and mouse SEAP gene expression in vivo was successfully maintained by both the MCK/SV40 and conventional promoters. These results suggest that the lower immunogenicity of the MCK/SV40 promoter contributed to long-lasting gene expression in mice. Therefore, the MCK/SV40 promoter may provide the basis for development of an effective transgene expression cassette for treatment of congenital protein deficiencies in which therapeutic proteins are recognized as foreign by the host immune system.

Animals↗
PubMed2006

Multivalent DNA vaccine protects mice against pulmonary infection caused by Pseudomonas aeruginosa.

For efficacious vaccine development against Pseudomonas aeruginosa (P. aeruginosa), the immunogenicity of multivalent DNA vaccine was evaluated. Three different plasmids each targeting a fusion of outer membrane proteins (OprF/OprI), a protein regulating type III secretion system (PcrV), or an appendage (PilA) were prepared and mice were immunized with single (monovalent) or a combination of these plasmids (multivalent) via intramuscular electroporation (imEPT) or gene gun. Immunization with multivalent DNA vaccine via imEPT induced the most potent protection against lethal pneumonia. Although the serum levels of IgG binding to whole bacteria cells were comparable between groups, the strongest immune protection was associated with the serum levels of Th1-dominated multivalent IgG, the bronchoalveolar levels of macrophage inflammatory protein 2 (MIP-2) and IFN-gamma, and the number of neutrophils and macrophages in the bronchoalveolar lavage following intranasal challenge. These results implied the possible clinical application of multivalent DNA vaccine against P. aeruginosa.

Animals↗
PubMed2006

High-level expression of pseudogenes in Mycobacterium leprae.

Recent studies have revealed that some RNAs are transcribed from noncoding DNA regions, including pseudogenes, and are functional as riboregulators. We have attempted to assess the gene expression profile throughout the Mycobacterium leprae genome using an array technique. Twelve highly expressed gene regions were identified that show an alteration in expression levels upon infection. Six of these were pseudogenes. Although M. leprae has an exceptional number and proportion of pseudogenes among species, our results suggest that some of the M. leprae pseudogenes are not just 'decayed' genes, but may have a functional role.

Animals↗
PubMed2006

Toll-like receptor adaptor molecules enhance DNA-raised adaptive immune responses against influenza and tumors through activation of innate immunity.

Toll-like receptors (TLRs) recognize microbial components and trigger the signaling cascade that activates the innate and adaptive immunity. TLR adaptor molecules play a central role in this cascade; thus, we hypothesized that overexpression of TLR adaptor molecules could mimic infection without any microbial components. Dual-promoter plasmids that carry an antigen and a TLR adaptor molecule such as the Toll-interleukin-1 receptor domain-containing adaptor-inducing beta interferon (TRIF) or myeloid differentiation factor 88 (MyD88) were constructed and administered to mice to determine if these molecules can act as an adjuvant. A DNA vaccine incorporated with the MyD88 genetic adjuvant enhanced antigen-specific humoral immune responses, whereas that with the TRIF genetic adjuvant enhanced cellular immune responses. Incorporating the TRIF genetic adjuvant in a DNA vaccine targeting the influenza HA antigen or the tumor-associated antigen E7 conferred superior protection. These results indicate that TLR adaptor molecules can bridge innate and adaptive immunity and potentiate the effects of DNA vaccines against virus infection and tumors.

Adaptor Proteins, Signal Transducing↗
PubMed2006

Nerve damage in Mycobacterium ulcerans-infected mice: probable cause of painlessness in buruli ulcer.

Buruli ulcer is an emerging chronic painless skin disease found in the tropics and caused by Mycobacterium ulcerans; however, it remains unknown why the large and deep ulcers associated with this disease remain painless. To answer this question, we examined the pathology of BALB/c mice inoculated in the footpads with M. ulcerans African strain 97-107. On days 54 to 70 after inoculation, extensive dermal ulcers, subcutaneous edema, and numerous acid-fast bacilli were noted at the inoculate region. Nerve invasion occurred in the perineurium and extended to the endoneurium, and some nerve bundles were swollen and massively invaded by acid-fast bacilli. However, Schwann cell invasion, a characteristic of leprosy, was not observed. Vacuolar degeneration of myelin-forming Schwann cells was noted in some nerves which may be induced by mycolactone, a toxic lipid produced by M. ulcerans. Polymerase chain reaction analysis of microdissected nerve tissue sections showed positive amplification of M. ulcerans-specific genomic sequences but not of Mycobacterium leprae-specific sequences. Behavioral tests showed decrease of pain until edematous stage, but markedly ulcerated animals showed ordinary response against stimulation. Our study suggests that the painlessness of the disease may be partly due to intraneural invasion of bacilli. Further studies of nerve invasion in clinical samples are urgently needed.

Animals↗
PubMed2006

[Guideline for the treatment of Hansen's disease in Japan (Second edition)].

ad hoc committee of Japanese Leprosy Association recommends revised standard treatment protocol of leprosy in Japan, which is a modification of World Health Organization's multidrug therapy (WHO/MDT, 1997). For paucibacillary (PB) leprosy, 6 months treatment by rifampicin and dapsone (MDT/PB) is enough. However, for high bacterial load multibacillary (MB) leprosy, 12 months treatment seems insufficient. Thus, (A) For MB with bacterial index (BI) > or = 3 before treatment, 2 years treatment by rifampicin, dapsone and clofazimine (MDT/MB) is necessary. When BI become negative and active lesion is lost within 2 years, no maintenance therapy is necessary. When BI is still positive, one year of MDT/MB is added (3 years in total), followed by maintenance therapy by dapsone and clofazimine until BI negativity and loss of active lesions. (B) For MB with BI < 3 or fresh MB (less than 6 months after the onset of the disease) with BI > or = 3, 1 year treatment by MDT/MB is necessary. When BI become negative and active lesion is lost within one year, no maintenance therapy is necessary. When BI is still positive or active lesion is remaining, additional therapy with MDT/MB for one more year is recommended. This is a simplification of first version in 2000. Brief summary of diagnosis, purpose of therapy, character of drugs, and prevention of deformity is also described.

Clofazimine↗
PubMed2006

[Future strategies for global leprosy control].

WHO has recently proposed a 5-year strategy plan for leprosy control beginning from 2006 to 2010. Even though currently there are still nine countries which have yet to achieve the goal of eliminating leprosy, it is considered to be accomplished in the near future. It is expected that the number of newly detected cases are expected to decline in the future by early detection, accurate diagnosis, early treatment, preventing disabilities and by further continuing the leprosy control activities.

Forecasting↗
PubMed2006

[Leprosy services following elimination in WPRO and SEARO regions].

The elimination of leprosy with the advent of multidrug therapy (MDT) is one of the success stories in public health. Elimination will be achieved in the regions of Western pacific and South-East Asia in near future. A biregional consultation between the WHO South-East Asia and Western Pacific regions was held in the end of 2004 in Manila, the Philippines. A strategy document was developed during the consultation, to sustain quality leprosy services in Asia and the Pacific beyond 2005, and to further reduce the leprosy burden. The main strategy involves timely detection of new cases, multidrug treatment, and the key element of integration of leprosy services into general health services.

Asia, Southeastern↗
PubMed2006

[Current practice of genetic diagnosis for Mycobacterium leprae].

Laboratory tests necessary for the diagnosis of leprosy have not been well introduced in general hospitals and clinical laboratories. Therefore, several tests have been performed in Leprosy Research Center, National Institute of Infectious Diseases since July, 1997, as a part of administrative examinations (tests done by request of Ministry of Health, Labour and Welfare). These examinations include histopathology, serum antibody titers (anti-PGL-I antibody), PCR test and bioactivity of anti-bacterial agents.

Humans↗
PubMed2006

[Leprosy and medicine I--proposal of an isolation policy and its background].

The leprosy policy of Japan began from when the government enacted "law No. 11 (The leprosy prevention act)" in 1907 (Meiji 40) and several leprosy sanatoriums were built and the patient who wanders about was received. Then, in rise of totalitarianism, the isolation policy of Japan gained national support under a slogan "Patient Relief", and it would become the big factor to which enactment of "Leprosy Prevention Law" in 1931 (Showa 6) and leprosy policy changed to segregation which aimed at internment of all leprosy patients. From today's research on the leprosy policy of Japan, it is internment of all leprosy patients, whole life isolation, social defense and neglect of patients' human-rights and led to many tragedy of patient. However, there is little research which can reply clearly to the question of whether the leprosy policy of Japan was really original and what the factors of led to the formation of the segregation policy. This paper focuses on the relation between leprosy policy and medicine, and from this, I make clear the similarity, or peculiarity of the isolation policy between Japan and the vest of the world, and clarify the factors of progress of the absolute isolation policy. The processes are historical and medical historical the verification of the relation between the formation of the national medicine and the progress of the isolation policy of Meiji Era, the proposal of the isolation policy by Dr. Keizo Dohi, Dr. Shibasaburo Kitasato, and Dr. Masatsugu Yamane, and the application by Dr. Kensuke Mitsuda, the decision to enact this policy and its support by the Health and Medical Bureau and the Department of the Interior, as well as many factors.

Health Policy↗
PubMed2006

[Situation of global leprosy].

The epidemiological situation of leprosy is reported by the health division of each country to WHO. The reported data is collected by WHO and is immediately run on the Weekly Epidemiological Record. On this latest edition, data from the beginning of 2005 was reported. According to this edition, the importance of the fact that nine countries in the world has yet to achieve the WHO goal of eliminating leprosy, early detection and constantly providing drugs free of charge, and continuing to carry out the leprosy control activities within the general health services.

Global Health↗
PubMed2006

Activator protein 1-mediated transcriptional regulation strategy sustains long-term expression of a xenogeneic gene product in vivo: an implication for gene therapy targeting congenital protein deficiencies.

Maintenance of high-level transgene expression is the main challenge in current gene therapy. Although the cytomegalovirus (CMV) promoter/enhancer or its derivative the CAG promoter has been harnessed in current gene therapy vectors, transgene expression by these vectors is often transient and remains at suboptimal levels due to undefined mechanisms, possibly including the shortage of transcriptional machinery. To overcome this drawback, we designed a novel transcriptional control system, designated here as transcription factor-supercharging promoter system, in which transgene expression is regulated by the positive feedback circuit consisting of cis- and trans-acting elements of gene expression machinery. Among combinations of these elements, a plasmid composed of a target gene expression cassette driven by the chimeric CMV promoter containing repetitive 12-O-tetradecanoylphorbol-13-acetate-responsive elements as cis-acting elements (CMV-TTT) and expression cassettes for c-Fos and c-Jun genes as trans-acting elements facilitated high and long-term (>10 months) expression of a transgene after its intramuscular electroporation-mediated delivery in mice. Since human secretory alkaline phosphatase was used as a reporter, it was suggested that the immune evasion mechanism elicited by the CMV-TTT and/or c-Fos/ c-Jun expression also contributed to the sustained expression in mice. Our strategy may open a new avenue for a gene therapy that involves lifelong supplementation of a deficient protein that could be targeted by the host's immune system.

Animals↗
PubMed2005

TRAF4 acts as a silencer in TLR-mediated signaling through the association with TRAF6 and TRIF.

Toll-like receptors (TLR) and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase play an essential role in intracellular eradication of engulfed pathogens. Here, we demonstrate the physical and functional association between components of the cytosolic NADPH oxidase and TLR-mediated signaling molecules. Cytosolic components of NADPH oxidase suppressed TLR-mediated NF-kappaB activation as well as IFN-beta promoter activation. We demonstrate that TNF-associated factor (TRAF) 4 associates with p47(phox), a component of cytosolic NADPH oxidase, and physically interacts and functionally counteracts with TRAF6 and Toll-IL-1 receptor (TIR) domain-containing adaptor-inducing IFN-beta (TRIF) molecules that critically regulate TLR-mediated signaling. TRAF4 mRNA expression was elicited in RPMI 8226 cells following LPS or CpG DNA treatment. These results suggest that TRAF4 participates in the molecular mechanism underlying silencing of TLR-mediated signaling through the interaction with molecules harboring phagosome/endosome membrane.

Adaptor Proteins, Vesicular Transport↗
PubMed2005

Immunostimulatory activity of major membrane protein-II from Mycobacterium leprae.

We examined the antigenicity of an immunomodulatory protein, major membrane protein (MMP)-II, from Mycobacterium leprae, since host defense against M. leprae largely depends on adaptive immunity. Both unprimed and memory T cells from healthy individuals were stimulated by autologous MMP-II-pulsed monocyte-derived dendritic cells (DCs) to produce IFN-gamma. The DC-mediated IFN-gamma production was dependent on the expression of MHC, CD86, and MMP-II antigens. Memory T cells from paucibacillary (PB) leprosy more extensively responded to MMP-II-pulsed DCs than T cells from healthy individuals, while comparable IFN-gamma was produced by unprimed T cells. Memory T cells from multibacillary leprosy, which are normally believed to be anergic, were activated similarly to those from healthy individuals by MMP-II-pulsed DCs. These results suggest that memory T cells from PB leprosy are primed with MMP-II prior to the manifestation of the disease, and MMP-II is highly antigenic in terms of activation of adaptive immunity.

Adult↗
PubMed2005

[Leprosy situation in Myanmar before and after multidrug therapy].

We introduced history of leprosy in Myanmar based on the book of Myanmar Academy of Medical Science published entitled "CONQUEST OF SCOURGES IN MYANMAR (Complied and Edited by Ko Ko, Kyaw and U Thaung) at 2002. "Leprosy Elimination Programme in Myanmar (Kyaw Lwin and Kyaw Nyunt Stein)" was appeared at chapter III in it. After dapsone treatment appeared, leprosy control program has started. Health system and service were developed and leprosy control program was also included in them. The integration of the elimination activities into basic health workers, such as midwives and health volunteers, has enabled the participation of a wide range of people in the community. After 1990s, multidrug therapy (MDT) was covered whole area of Myanmar, and task force for leprosy elimination was formed at Sate/Division, District and Township level. Finally Myanmar achieved the elimination of leprosy in January in 2003.

Dapsone↗
PubMed2004

Transcriptional regulation of the human TLR9 gene.

To clarify the molecular basis of human TLR9 (hTLR9) gene expression, the activity of the hTLR9 gene promoter was characterized using the human myeloma cell line RPMI 8226. Reporter gene analysis and EMSA demonstrated that hTLR9 gene transcription was regulated via four cis-acting elements, cAMP response element, 5'-PU box, 3'-PU box, and a C/EBP site, that interacted with the CREB1, Ets2, Elf1, Elk1, and C/EBPalpha transcription factors. Other members of the C/EBP family, such as C/EBPbeta, C/EBPdelta, and C/EBPepsilon, were also important for TLR9 gene transcription. CpG DNA-mediated suppression of TLR9 gene transcription led to decreased binding of the trans-acting factors to their corresponding cis-acting elements. It appeared that suppression was mediated via c-Jun and NF-kappaB p65 and that cooperation among CREB1, Ets2, Elf1, Elk1, and C/EBPalpha culminated in maximal transcription of the TLR9 gene. These findings will help to elucidate the mechanism of TLR9 gene regulation and to provide insight into the process by which TLR9 evolved in the mammalian immune system.

Animals↗