PubMed Health⌕ Search

Biomedical subjects

Hideyo Yamaguchi

Publications and source records attributed to Hideyo Yamaguchi.

At least 37 records · Page 2Linked to original sources
PubMed2005

A novel mycological analysis valuable for evaluating therapeutic efficacy of antimycotics against experimental dermatophytosis in guinea pigs.

Although antimycotic effects are mainly evaluated with regard to whether or not the fungi grow from a specimen obtained from the drug-treated skin, the potential for discrepancies in skin specimens in which the fungi are grown has not been evaluated, in the experimental tinea model. In this study, to evaluate the therapeutic effectiveness of antimycotic agents against fungal skin infection, a novel form of mycological assessment, which focuses on the size of colonies grown from skin specimens was examined and developed. When microconidia of Trichophyton mentagrophytes were inoculated onto a Sabouraud dextrose agar (SDA) plate and incubated at 27 degrees C for 5 days, a linear relationship was observed between the growth area of mycelia and the logarithm of the quantity of microconidia. This relationship between the growth area and the logarithm of the number of T. mentagrophytes microconidia did not change with the addition of skin homogenate and/or keratin powder. Next, the number of fungi in skin blocks attendant upon experimental, cutaneous infection in guinea pigs was evaluated and analyzed via a calibration curve, determined based on a microconidium suspension of T. mentagrophytes. Estimates of severity of dermatophytic infection in experimental animals were parallel to, but more reliable than, results obtained via the conventional mycological method (fungus-positive skin ratio of treated skin) in culture studies of infected dermal tissues. This new analytical method may also be applicable to the in vivo assessment of the therapeutic effect against dermatophytosis experimentally produced in guinea pigs.

Animals↗
PubMed2005

Protection of oral or intestinal candidiasis in mice by oral or intragastric administration of herbal food, clove (Syzygium aromaticum).

We examined the effect of a clove (Syzygium aromaticum) administered by two different routes on Candida albicans growth, using a murine oral candidiasis model. When the clove preparation was administered into the oral cavity of Candida-infected mice, their oral symptoms were improved and the number of viable Candida cells in the cavity was reduced. In contrast, when the clove preparation was administered intragastrically, oral symptoms were not improved, but viable cell numbers of Candida in the stomach and feces were decreased. These findings demonstrate that oral intake of an herbal food, clove, may suppress the overgrowth of C. albicans in the alimentary tract including the oral cavity.

Animals↗
PubMed2005

Metalloprotease gene of Arthroderma gypseum.

The full-length cDNA sequence for metalloprotease (MEP) of Arthroderma gypseum (one of the teleomorphs of the Microsporum gypseum complex) was determined by the 5'-rapid amplification of cDNA ends (RACE) and 3'-RACE methods using cDNA as a template. The full-length cDNA sequence of the MEP (2,670 bp) gene was proved to encode 677 amino acids. The amino acid sequence of the A. gypseum MEP gene shared about 89 and 66% sequence similarity with the conserved region of the Microsporum canis MEP gene and Aspergillus fumigatus, respectively. Southern hybridization analysis of genomic DNA with an MEP probe gave many distinct bands in BamHI, EcoRI and HindIII digests of genomic DNA from A. gypseum. Reverse transcriptase-PCR analysis suggested that keratin might stimulate the expression of MEP mRNA in A. gypseum.

Amino Acid Sequence↗
PubMed2005

Differentiation of Candida albicans and Candida dubliniensis using a single-enzyme PCR-RFLP method.

Candida dubliniensis is a novel Candida spp. that is similar to Candida albicans with respect to several phenotypic characteristics. However, they differ from each other with respect to epidemiology, pathogenesis, and the rapid development of resistance to fluconazole. In the present study, we used a single-enzyme PCR-restriction fragment length polymorphism (RFLP) technique to differentiate C. dubliniensis from C. albicans. The amplified ITS region of C. dubliniensis was digested once using the enzyme B1nI, whereas that of C. albicans remained intact. All standard strains tested were identified successfully by this method. None of 140 clinical isolates identified morphologically as C. albicans were recognized as C. dubliniensis based on their PCR-RFLP pattern. Our PCR-RFLP method easily differentiated C. dubliniensis from C. albicans, and this result was also demonstrated with standard strains.

Adult↗
PubMed2004

Reduced activity of Candida detachment factors in the saliva of the elderly.

Saliva in healthy human subjects contains protenaceous factors that detach Candida albicans cells from plastic plates. To investigate the physiological role of the detachment activity of human saliva, we compared the activity of salivary specimens collected from the elderly (who are at greater risk of oral candidiasis) to the activity of specimens collected from children and nonelderly adults. C. albicans cells were cultured and attached to the bottoms of the wells of a 96-well plate, and saliva preparations were then added to each well. After 3 h of incubation, Candida cells attached to the bottoms of the wells were counted, using the crystal violet staining method. The results showed that the activity of salivary detachment factors was significantly lower among the elderly than among nonelderly adults and children. Furthermore, the activity of salivary detachment factors was reduced in 12 of the 43 elderly subjects (27.9%), a significantly higher proportion relative to that in the children and nonelderly adults. However, there was no significant difference in the level of salivary proteins between the samples collected from elderly subjects displaying low and high salivary detachment activity. These results suggest that the increased number of people with lower salivary detachment activity among the elderly may be one of the reasons that oral candidiasis is more common among the elderly than in nonelderly adults and children.

Adult↗
PubMed2004

Augmented inhibition of Candida albicans growth by murine neutrophils in the presence of a tryptophan metabolite, picolinic acid.

The effects of picolinic acid (PLA), a product of tryptophan catabolism, on anti- Candida activity of neutrophils were studied. Casein-induced peritoneal neutrophils of C3H/He mice partially inhibited mycelial growth of Candida albicans when cultured with C. albicans for 16 h in vitro. The growth inhibition of Candida was augmented by a combination of neutrophils and more than 4 mM picolinic acid. Especially in the presence of 200 U/ml murine interferon-gamma (IFN-gamma), 2 mM picolinic acid augmented the anti- Candida activity of neutrophils. The physiological significance of the augmenting effects of picolinic acid is discussed.

Animals↗
PubMed2004

In vitro antifungal activity of luliconazole (NND-502), a novel imidazole antifungal agent.

The in vitro activity of luliconazole (NND-502), a novel imidazole antifungal agent, against dermatophytes and several other groups of medically important fungi including the rare causative agents of dermatomycoses, was studied. The luliconazole susceptibility tests were performed with a total of 58 fungal strains of 23 species of fungi grouped into dermatophytes, dematiaceous fungi, hyaline hyphomycetes, yeastlike fungi, and zygomycetes using a broth microdilution method with RPMI 1640 medium. The minimum inhibitory concentration (MIC) values for luliconazole were compared with those of three reference drugs, lanoconazole (LCZ), bifonazole (BFZ), and terbinafine (TBF), all of which have been popular for the topical treatment of dermatophytosis, cutaneous candidiasis, and other superficial fungal infections in Japan. Luliconazole inhibited growth of all filamentous fungi except zygomycetes at low concentrations (MIC, < or =0.004-0.125 microg/ml), with dermatophytes being most susceptible (MIC, < or =0.004-0.008 microg/ml). The susceptibility of these filamentous fungi to luliconazole was almost equal to that to LCZ, and surpassed TBF and BFZ, although to a lesser extent; yeastlike fungi were also susceptible to luliconazole (MIC, 0.125-4 microg/ml). Again the anti-yeastlike fungi activity of luliconazole was at the same level as LCZ and was greater than that of BFZ and TBF. In contrast to BFZ and TBF, however, luliconazole and LCZ were virtually inactive against zygomycetes.

Antifungal Agents↗
PubMed2004

Protective effects of human saliva on experimental murine oral candidiasis.

The protective effects of human saliva, known to contain various proteinaceous factors that have anti- Candida activity in vitro on oral candidiasis in the mouse model, were examined in vivo. Oral candidiasis was established by oral inoculation of viable Candida albicans (C. albicans) cells to ICR mice, 24 h after administration of predonisolone. These mice received orally 0.1 ml human saliva or sterile distilled water into the oral cavity a total of five times at specific intervals: 3, 6, 12, 24, and 36 h after inoculation. Seventy-two hours after inoculation with C. albicans, viable C. albicans cells in the oral cavity of the mice were counted and a subjective score for the extent of white patches on the tongue surface determined. The results showed that viable counts were significantly lower in the human saliva group than in the distilled water group (P < 0.05). Scores for white patches on the tongue were also significantly lower in the saliva group than in the distilled water group (P < 0.05). These results suggest that administration of human saliva may inhibit the colonization of the oral cavity by C. albicans in mice and the subsequent onset of oral candidiasis.

Animals↗
PubMed2004

Potential usefulness of bovine lactoferrrin for adjunctive immunotherapy for mucosal Candida infections.

Immunosuppressed children and adults have a higher prevalence of oropharyngeal candidiasis. In this patient population, anti-fungal therapy of this condition is often ineffective, and new approaches to treatment are needed. The use of bovine lactoferrin is considered a promising option in treating oropharyngeal candidiasis. Here we review the results of in vitro and in vivo studies that have examined the antimicrobial characteristics of bovine lactoferrin as an adjunctive therapy for oropharyngeal candidiasis.

Animals↗
PubMed2004

Modulation of the human interleukin-12p40 response by a triazole antifungal derivative, itraconazole.

Some types of antimicrobial agents such as fosfomycin, clarithromycin, and erythromycin have been known to affect the host's immunological response. We investigated whether itraconazole (ITCZ) can modulate the serum cytokine levels (tumor necrosis factor (TNF-alpha, interleukin (IL)-10, IL-12p40) in both patients and healthy subjects. Serum samples were collected and TNF-alpha, IL-10 and IL-12p40 were measured using a sandwich enzyme-linked immunosorbent assay (ELISA). We showed increased levels of IL-12p40 in patients treated with ITCZ. In healthy subjects, moreover, ITCZ treatment significantly increased the production of IL-12p40, but not TNF-alpha or IL-10. These findings suggest that the effectiveness of ITCZ in the treatment of fungal infection may be due not only to its direct antifungal effect, but also to induction of an immunomodulative effect on the host defense systems by regulation of cytokine production.

Adult↗
PubMed2004

A multicenter, open-label clinical study of micafungin (FK463) in the treatment of deep-seated mycosis in Japan.

The efficacy and safety of micafungin (FK463), which is a new lipopeptide antifungal agent of the echinocandin class and is active against both Aspergillus and Candida species, were investigated in patients with deep-seated mycosis in this study. 70 patients were treated with micafungin 12.5-150 mg/d intravenously for up to 56 d. The overall clinical response rates were 60% (6/10) in invasive pulmonary aspergillosis, 67% (6/9) in chronic necrotizing pulmonary aspergillosis, 55% (12/22) in pulmonary aspergilloma, 100% (6/6) in candidemia, and 71% (5/7) in esophageal candidiasis. The response rates for patients with prior antifungal treatment which was considered ineffective or toxic, were similar to rates for patients without prior treatment. Mycological eradication was observed in patients infected with Aspergillus fumigatus, Aspergillus flavus, Aspergillus terreus, Aspergillus niger, Candida albicans, Candida glabrata, or Candida krusei. Adverse events related to micafungin were reported in 21 patients (30%), and there was no dose-related occurrence of any adverse event. It is concluded that treatment with micafungin as monotherapy seems to be effective and safe in patients with deep-seated mycosis.

Adult↗
PubMed2004

Production of anti-Candida antibodies in mice with gut colonization of Candida albicans.

BACKGROUND: Production of antibodies that are specific for allergens is an important pathological process in inflammatory allergic diseases. These contain the antibodies against antigens of Candida albicans, one of the normal microbial flora in an intestinal tract. We studied the effects of the prednisolone administration on the production of anti-Candida antibodies in the gastrointestinally C. albicans-colonized mice. METHODS AND MATERIALS: BALB/c mice, treated with antibacterial antibiotics to decontaminate indigenous intestinal bacterial flora, were inoculated intragastrically with C. albicans. The mice, in which C. albicans grows intestinally, were administered prednisolone to induce temporary immunosuppression. The Candida growth in their intestinal tract and their antibody response to Candida were examined. RESULTS: Antibiotic treatment allowed establishment of C. albicans gastrointestinal colonization, but did not cause subsequent systemic dissemination of C. albicans in all the animals. When these animals received an additional treatment with prednisolone, they showed a significantly higher population of C. albicans in their feces than those of animals treated with antibiotics alone, and the organisms were recovered even from their kidney. This systemic dissemination by C. albicans appeared to be temporal, because all the mice survived without any symptoms for more than 2 months. Examination of the serum titers of total immunoglobulin (Ig)E antibodies and specific IgE and IgG antibodies against Candida antigens demonstrated that titers of total IgE increased, partially by day 14 and clearly at day 27, in prednisolone-treated Candida-colonized mice. Without prednisolone treatment, an increment of the serum titer was scarcely observed. By day 27, corresponding to the increase of total IgE, the anti-Candida IgE and IgG titer increased in mice of the prednisolone-treated group. CONCLUSION: Administration of prednisolone to Candida-colonized mice can induce production of the IgG, IgE antibodies against Candida antigens, perhaps through temporal systemic dissemination of Candida from the intestinal tract.

Animals↗
PubMed2004

Suppression of neutrophil recruitment in mice by geranium essential oil.

BACKGROUND: In aromatherapy, essential oils are used as anti-inflammatory remedies, but experimental studies on their action mechanisms are very limited. AIMS OF THE STUDY: To assess their anti-inflammatory activities, the effects of essential oils on neutrophil recruitment in mice were examined in vivo. METHOD: The effect of essential oils on leukocyte and neutrophil recruitment induced 6 h after intraperitoneal injection of casein in mice was examined. RESULTS: Leukocyte recruitment into the peritoneal cavity in mice was suppressed by intraperitoneal injections of geranium, lemongrass and spearmint oils at the dose of 5 microl/mouse, but was not by tea tree oil. This recruitment was inhibited dose-dependently by geranium oil. The suppression of leukocyte recruitment resulted from inhibition of neutrophil accumulation. CONCLUSION: Some essential oils used as anti-inflammatory remedies suppress neutrophil recruitment into the peritoneal cavity in mice.

Animals↗
PubMed2004

PCR identification system for the genus Aspergillus and three major pathogenic species: Aspergillus fumigatus, Aspergillus flavus and Aspergillus niger.

A PCR system was developed that allowed recognition of three major pathogenic Aspergillus species, namely A. fumigatus, A. niger and A. flavus, in isolates obtained from clinical specimens. The primer pair for PCR was designed from conserved sequences of internal transcribed spacer 1 (ITS1) ribosomal DNA and its flanking regions. Products 521 bp in size were successfully amplified by PCR from the seven Aspergillus species most frequently encountered as opportunistic pathogens, and the three most commonly significant species were identified by separate PCR reactions or nested PCR based on use of species-specific primers. To our knowledge, this is first report of identification of the second and third most frequent pathogenic Aspergillus species using specific PCR amplification. The PCR based identification system reported here will be a powerful tool to control difficult pulmonary fungal infections and to speed the application of effective treatment.

Aspergillus flavus↗
PubMed2004

Malassezia nana sp. nov., a novel lipid-dependent yeast species isolated from animals.

Five isolates of a novel species of the yeast genus Malassezia were isolated from animals in Japan and Brazil. Phylogenetic trees based on the D1/D2 domains of the large-subunit (26S) rDNA sequences and nucleotide sequences of the internal transcribed spacer 1 region showed that the isolates were conspecific and belonged to the genus Malassezia. They were related closely to Malassezia dermatis and Malassezia sympodialis, but were clearly distinct from these two species and the other six species of Malassezia that have been reported, indicating that they should be classified as a novel species, Malassezia nana sp. nov. Morphologically and physiologically, M. nana resembles M. dermatis and M. sympodialis, but can be distinguished from these species by its inability to use Cremophor EL (Sigma) as the sole lipid source and to hydrolyse aesculin. The type strain of M. nana is NUSV 1003(T) (=CBS 9557(T)=JCM 12085(T)).

Animals↗
PubMed2004

Effect of orally administered bovine lactoferrin on the immune response in the oral candidiasis murine model.

Therapeutic activity against oral candidiasis of orally administered bovine lactoferrin (LF), a multifunctional milk protein, was shown in a previous report using an immunosuppressed murine model. In the present study, the influence of orally administered LF on immune responses relevant to this therapeutic effect was examined. Because mice were immunosuppressed with prednisolone 1 day before and 3 days after the infection with Candida, the numbers of peripheral blood leukocytes (PBL) and cervical lymph node (CLN) cells were reduced. LF feeding prevented the reduction in the numbers of PBL on day 1 and CLN cells on days 1, 5 and 6 in the Candida-infected mice. The number of CLN cells of individual mice on days 5 and 6 was inversely correlated with the Candida c.f.u. in the oral cavity. Increased production of IFN-gamma and TNF-alpha by CLN cells stimulated with heat-killed Candida albicans on day 6 was observed in LF-treated mice compared with non-treated mice. Concanavalin A (ConA)-stimulated CLN cells from LF-treated mice also showed a significant increase in the production of IFN-gamma and IL12 on day 5 and a tendency for increased production of IFN-gamma and TNF-alpha on day 6. The levels of cytokine production by ConA-stimulated CLN cells on day 6 were inversely correlated with the Candida c.f.u. in the oral cavity. In conclusion, the alleviation of oral candidiasis by LF feeding in this model may correlate with the enhancement of the number of leukocytes and their cytokine responses in regional lymph nodes against Candida infection.

Adjuvants, Immunologic↗