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Masanori Matsuoka

Publications and source records attributed to Masanori Matsuoka.

At least 19 recordsLinked to original sources
PubMed2006

Genotypic analysis of Mycobacterium leprae isolates from Japan and other Asian countries reveals a global transmission pattern of leprosy.

The genotype of single-nucleotide polymorphism type 3, CTC, at positions 14676, 164275, and 2935685, along with four copies of 6 bp repeats in the rpoT gene, was predominant for isolates originating in the Japanese mainland. Type 1, CGA, type 2, CTA, and type 3 were detected from Korea, Indonesia, and Myanmar. No isolates with four copies of 6 bp were detected from Myanmar, Okinawa, and Japanese Brazilian patients. Type 4, TTC, with three copies of 6 bp, was detected only from Japanese Brazilians. The results indicate that infection occurred in Brazil and the disease developed later in Japan.

Adolescent↗
PubMed2006

[Basic evaluation for new antimicrobial susceptibility testing of Mycobacterium leprae by bioluminescence assay (ATP method)].

Antimicrobial susceptibility testing of Mycobacterium leprae by non-radioactive bioluminescence assay was developed. Optimization of the assay conditions such as temperature and time for ATP extraction, bacteria dose, preparation of bacteria suspension and pH of culture medium was carried out using M. leprae Thai 53 strain. Samples of bacterial suspension of M. leprae were first treated with filamentous cell treatment reagent at room temperature for 30 minutes and ATP was extracted from the leprosy bacilli by heating at 60 degrees for five minutes. Luciferin luciferase was added to the extract after cooling to room temperature followed by measurement of relative light units (RLU) of each sample using a luminometer. The concentrations of the drugs used for the evaluation of antimicrobial activities of rifampin (RFP), clofazimine (CLF), ofloxacin (OFLX) and clarithromycin (CAM) were 0.125, 0.50, 2.0 and 8.0 microg/ml respectively. Middlebrook 7H9 broth medium was used (pH6.6) as the basal medium and the bacilli were cultivated at 32 C for 0-14 days. ATP was extracted from 0.1 ml of culture suspension and inhibition of the luminescent activity was calculated. The results were compared to that obtained by radio-active CO2 detection system, Buddemeyer method which is commonly used for measuring anti-M. leprae activity. There was a good correlation between the results obtained by ATP method on the tenth day of culture and the results obtained by Buddemeyer method on the seventh day of culture. ATP method may be useful for the determination of drug susceptibility ofM. leprae.

Animals↗
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

[DNA microarray based rapid drug susceptibility test for Mycobacterium leprae].

Antibiotic susceptibility test of Mycobacterium leprae still relies on the time consuming methods based on the growth of M. leprae in the mouse footpad. Thus, the establishment of a rapid, simple and reliable method for the detection of drug-resistant M. leprae is one of the most urgent subjects in the treatment of leprosy patients. Recently, many data on the mutation of specific genes correlating with drug resistance have been accumulated. Application of these data permit the establishment of new gene diagnostic methods for drug susceptibility test of leprosy. In this paper, the method using the low density oligonucleotide array that enables the detection of base substitutions involved in resistance against anti-leprosy drugs on a single platform was discussed. The low density oligonucleotide array described in this paper will open the new perspectives in terms of patient management for leprosy with low cost requirement.

Animals↗
PubMed2005

Polymorphism in the rpoT gene in Mycobacterium leprae isolates obtained from Latin American countries and its possible correlation with the spread of leprosy.

The genotypes of Mycobacterium leprae isolates originating from Mexico, Peru and Paraguay were analysed for the polymorphism of short tandem repeats in the rpoT gene. The genotype with four copies of the six-base tandem repeats in the rpoT gene was prominently predominant in Mexico, but the genotype of all isolates from Peru and Paraguay contained three copies of the six-base tandem repeats. These obvious different distributions might reflect the spread of leprosy by the different strains of M. leprae harboured by the various human races that moved to the American continent, as has been demonstrated in other infectious diseases.

Bacterial Proteins↗
PubMed2005

Diversity of potential short tandem repeats in Mycobacterium leprae and application for molecular typing.

A recent advance in molecular typing for tracing the transmission of leprosy is the discovery of short tandem repeats (STRs) in Mycobacterium leprae. To substantiate polymorphic loci from STR as promising candidates for molecular typing tools in leprosy epidemiology, 44 STR loci including 33 microsatellites and 11 minisatellites were investigated among 27 laboratory strains by sequencing PCR products. Not all STRs were necessarily polymorphic. Thirty-two out of the 44 loci were polymorphic. Nine polymorphic loci were suitable for identifying genotypes according to the discriminatory capacity, stability, and reproducibility. All the strains were classified into independent genotypes by the selected nine loci. Three multi-case households were subjected to molecular typing. M. leprae obtained from household cases showed identical copy numbers by TTC triplet alone, but the isolates from one family contact case were divided into different genotypes by adding eight other polymorphic loci. The combination of information from multiple loci allows increasing levels of discrimination and it is likely that the generation and documentation of data will result in the choice of a potential molecular typing tool for leprosy epidemiology.

Animals↗
PubMed2005

[Current advances in leprosy research activities].

Due to the advent of multi-drug therapy (MDT) recommended by the WHO, for the treatment of leprosy, presently, leprosy is regarded as a "curable disease". The number of new cases in Japan is relatively very low, due to which the disease is likely to be neglected, but on scientific grounds, there is a necessity to perform in depth studies. Leprosy caused by M. leprae is still unclear on various aspects including transmission, immunology, nerve damage etc. Here we introduce the recent advances in the field of basic leprosy research.

Animals↗
PubMed2004

Effects of scaling and root planing on the amounts of interleukin-1 and interleukin-1 receptor antagonist and the mRNA expression of interleukin-1beta in gingival crevicular fluid and gingival tissues.

OBJECTIVE: The purpose of this study was to evaluate the relationship between the clinical changes after non-surgical periodontal therapy and interleukin 1 (IL-1) in gingival crevicular fluid (GCF) and gingival tissues from patients with chronic periodontitis. BACKGROUND: The inflammatory responses mediated by IL-1 play an important role in periodontal tissue destruction. Although numerous studies have attempted to elucidate the dynamic movement involved in chronic periodontitis, the results have often conflicted. Such discrepancies may have been due to the inability to determine clinical disease activity. METHODS: Seven patients with chronic periodontitis were examined. The severity of periodontal inflammation was expressed using clinical parameters before and after a scaling and root planing (SRP) procedure. The amounts and concentrations of IL-1alpha, IL-1beta and IL-1 receptor antagonist in GCF were measured by enzyme-linked immunosorbent assay (ELISA) and IL-1 activity index was calculated. A needle biopsy in matching gingival tissues was also performed before and after the SRP procedure. The localization and mRNA expression of IL-1beta were determined using histological methods. RESULTS: Clinical parameters improved slightly after the SRP procedure. Only the probing pocket depth (PPD) was reduced significantly (p < 0.05). However, the amount of IL-1beta in GCF was slightly increased. The localization and mRNA expression of IL-1beta could still be observed after the SRP procedure. Therefore, none of the clinical parameters showed a high sensitivity or specificity for evaluating subgingival inflammation. CONCLUSION: These observations suggest that IL-1 is effective for evaluating in detail the state of subgingival inflammation.

Adult↗
PubMed2004

Genotyping of Mycobacterium leprae on the basis of the polymorphism of TTC repeats for analysis of leprosy transmission.

The polymorphism of TTC repeats in Mycobacterium leprae was examined using the bacilli obtained from residents in villages at North Maluku where M. leprae infections are highly endemic (as well as from patients at North Sulawesi of Indonesia) to elucidate the possible mode of leprosy transmission. TTC genotypes are stable for several generations of passages in nude mice footpads and, hence, are feasible for the genotyping of isolates and epidemiological analysis of leprosy transmission. It was found that bacilli with different TTC genotypes were distributed among residents at the same dwelling in villages in which leprosy is endemic and that some household contacts harbored bacilli with a different genotype from that harbored by the patient. Investigations of a father-and-son pair of patients indicated that infections of bacilli with 10 and 18 copies, respectively, had occurred. Genotypes of TTC repeats were found to differ between a son under treatment and two brothers. These results reveal the possibility that in addition to exposure via the presence of a leprosy patient with a multibacillary infection who was living with family members, there might have been some infectious sources to which the residents had been commonly exposed outside the dwellings. A limited discriminative capacity of the TTC polymorphism in the epidemiological analysis implies the need of searching other useful polymorphic loci for detailed subdivision of clinical isolates.

Animals↗
PubMed2004

IL-10 treatment of macrophages bolsters intracellular survival of Mycobacterium leprae.

In these studies, metabolically active Mycobacterium leprae were maintained for as long as 8 weeks in monolayer cultures of mouse peritoneal macrophages (MPhi). Supplemental IL-10, but not TGF-beta, bolstered, directly or indirectly, M. leprae metabolism in mouse MPhi. In the cell culture system temperature setting is extremely important and 31 to 33 degrees C incubation temperature was more permissive than 37 degrees C. Acid fast staining and transmission electron microscopy (TEM) of intracellular M. leprae revealed visible elongation of bacilli cultured under the above ideal conditions.

Animals↗
PubMed2004

A mutation at codon 516 in the rpoB gene of Mycobacterium leprae confers resistance to rifampin.

A missense mutation at codon 516 in the rpoB gene of Mycobacterium leprae conferring rifampin resistance was confirmed by the correlation between sequencing results and mouse footpad assay. The isolate was obtained from a relapsed lepromatous leprosy patient. This is the first report on the complete concordance between the mutation located at codon 516 in the rpoB gene and the corresponding resistance to rifampin in leprosy. The novel profile of mutation in the rpoB gene will contribute to the comprehensive understanding of rifampin resistant patterns and offer a useful tool for developing simple and rapid drug susceptibility testing approaches, which would promise more effective and successful control of leprosy.

Aged↗
PubMed2004

[Molecular epidemiology of the leprosy].

Application of molecular biological techniques to the epidemiological study of leprosy is described. Studies of detecting Mycobacterium leprae DNA in samples of the nasal mucus are discussed in terms of the epidemiology and the significance of high prevalence. Epidemiological studies on the transmission of leprosy and correlation between geographic distribution of different M. leprae rpoT genotypes and prehistoric spread of the leprosy by genotyping based on the genomic polymorphism are introduced.

Animals↗
PubMed2003

Degradation process of Mycobacterium leprae cells in infected tissue examined by the freeze-substitution method in electron microscopy.

Mycobacterium leprae cells (strain Thai-53) harvested from infected mouse foot pads were examined by electron microscopy using the freeze-substitution technique. The population of M. leprae cells from the infected tissue consisted of a large number of degraded cells and a few normal cells. These thin sectioned cell profiles could be categorized into four groups depending on the alteration of the membrane structures, and the degradation process is considered to occur in stages, namely from stages 1 to 3. These are the normal cells with an asymmetrical membrane, a seemingly normal cell but with a symmetrical membrane (stage 1), a cell possessing contracted and highly concentrated cytoplasm with a membrane (stage 2), and a cell that has lost its membrane (stage 3). The peptidoglycan layer was found to remain intact in these cell groups.

Animals↗
PubMed2003

Comparative studies of the cell structures of Mycobacterium leprae and M. tuberculosis using the electron microscopy freeze-substitution technique.

The cell envelope and cytoplasmic architecture of the Mycobacterium leprae Thai-53 strain were examined using the freeze-substitution technique of electron microscopy and compared with those of the M. tuberculosis H37Rv strain. Both strains had similarly multilayered envelope architectures composed of an electron-translucent layer, a peptidoglycan layer and the plasma membrane, from outside to inside. A comparison of the structures of these two mycobacteria revealed that the M. leprae cell was smaller in size and had a thinner peptidoglycan layer than the M. tuberculosis cell. The cell widths measured on electron micrographs were 0.44 microm for M. tuberculosis and 0.38 microm for M. leprae. The peptidoglycan layer of M. leprae was 4-5 nm, while the corresponding layer of M. tuberculosis was 10-15 nm.

Animals↗
PubMed2003

A second case of multidrug-resistant Mycobacterium leprae isolated from a Japanese patient with relapsed lepromatous leprosy.

Emergence of drug resistant strains of Mycobacterium leprae was reported soon after the introduction of dapsone (diamino-diphenyl sulphone, DDS) for leprosy treatment (6, 10, 11). Three cases of multidrug-resistant strains of M. leprae have been reported recently (2, 8, 9, 13). In order to prevent multiple drug resistant strains of M. leprae from developing, current leprosy control strategies are based on early detection of cases and treatment with multidrug therapy (MDT) as recommended by the World Health Organization (WHO). We report here the identification of a multidrug-resistant strain of M. leprae from a patient who received inadequate therapy for leprosy. The drug resistant profile of the isolated strain was confirmed by the mouse footpad method and the identification of mutations in genes previously shown to be associated with resistance to each drug was made.

Aged↗
PubMed2002

Mycobacterium leprae infection in monocyte-derived dendritic cells and its influence on antigen-presenting function.

Host defense against Mycobacterium leprae infection is chiefly mediated by gamma interferon (IFN-gamma)-secreting cytotoxic T cells. Since which antigen-presenting cell populations act to stimulate these T cells is not fully understood, we addressed the role of monocyte-derived dendritic cells (DCs). The DCs phagocytosed M. leprae and expressed bacterially derived antigens (Ags), such as phenolic glycolipid 1 (PGL-1), in the cytoplasm, as well as on the cell surface. The expression of HLA-ABC and -DR Ags on DCs was down-regulated by M. leprae infection, and that of CD86 was up-regulated, but not as fully as by Mycobacterium bovis BCG infection. Induction of CD83 expression required a large number of M. leprae cells. When a multiplicity of infection of >40 was used, the DCs induced a significant proliferative and IFN-gamma-producing response in autologous T cells. However, these responses were significantly lower than those induced by BCG- or Mycobacterium avium-infected DCs. A CD40-mediated signaling in M. leprae-infected DCs up-regulated the expression of HLA Ags, CD86, and CD83 but did not enhance T-cell-stimulating ability. Therefore, M. leprae-infected DCs are less efficient at inducing T-cell responses. However, when the surface PGL-1 on M. leprae-infected DCs was masked by a monoclonal antibody, the DCs induced enhanced responses in both CD4(+)- and CD8(+)-T-cell subsets. M. leprae is a unique pathogen which remains resistant to DC-mediated T-cell immunity, at least in the early stages of infection.

Antibodies, Monoclonal↗