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Biomedical subjects

Hideyo Yamaguchi

Publications and source records attributed to Hideyo Yamaguchi.

At least 19 recordsLinked to original sources

Oral administration of itraconazole solution has superior efficacy in experimental oral and oesophageal candidiasis in mice than its intragastric administration.

OBJECTIVE: The therapeutic activities of cyclodextrin-associated itraconazole oral solution (itraconazole OS) by two administration routes in experimental oral and oesophageal candidiasis in mice were examined and compared. METHODS: Using experimental oral and oesophageal candidiasis models in ICR mice, we investigated the efficacy of oral and intragastric administration of itraconazole OS and checked the concentration of itraconazole and its metabolite hydroxyitraconazole (OH-itraconazole) in tongues or oesophagus tissue after administration of itraconazole OS. RESULTS: Oral administration of itraconazole OS at doses of 0.8, 4.0 or 20 mg/kg/day clearly decreased the number of viable Candida albicans cells in the oral cavity of mice with oral candidiasis in a dose-dependent manner at 3 days after infection. Intragastric administration of itraconazole OS at doses of 4 and 20 mg/kg/day once a day were also effective but to a lesser degree than that of oral administration. In the oesophageal candidiasis model, oral administration of itraconazole OS displayed superior therapeutic efficacy to the intragastric route. In coincidence with the greater efficacy, itraconazole was detected in lesional tissues after oral administration of itraconazole OS. CONCLUSIONS: Oral administration of itraconazole OS displayed therapeutic efficacy against murine oral and oesophageal candidiasis superior to that achieved by intragastric administration. This can be explained by there being higher concentrations of itraconazole in tongues or oesophagus tissues after administration of the suspension by the oral route.

Administration, Oral↗

Anti-tumor activities of the antlered form of Ganoderma lucidum in allogeneic and syngeneic tumor-bearing mice.

We investigated the anti-tumor effects of a dry powder preparation of the antlered form of Ganoderma lucidum (G. lucidum AF, rokkaku-reishi in Japanese), a variant type of G. lucidum, not only in allogeneic Sarcoma 180-bearing ddY mice, but also in syngeneic MM 46-bearing C3H/He mice. G. lucidum AF inhibited tumor growth and elongated the life span when orally administered to mice by free-feeding of a 2.5% G. lucidum AF-containing diet. It also showed anti-tumor activity in spite of post-feeding after tumor inoculation. G. lucidum AF significantly countered the depression of splenic CD8+ cells and protected the decrease in interferon-gamma (IFN-gamma) production in regional lymph nodes of MM 46-bearing mice, indicating that the anti-tumor activity of G. lucidum AF might be caused by its immunostimulating action. These results suggest that the ingestion of G. lucidum AF can be useful for the prevention and curing of cancer.

Animals↗

Rapid identification of Trichophyton tonsurans by specific PCR based on DNA sequences of nuclear ribosomal internal transcribed spacer (ITS) 1 region.

BACKGROUND: Trichophyton tonsurans, a dermatophyte implicated in an international epidemic of tinea capitis, was also found to be responsible for infecting wrestling and Judo athletes nationwide in Japan since 2001. OBJECTIVE: A rapid and highly accurate means of identifying this pathogen has been required to control the infection. We have developed a T. tonsurans-specific PCR method based on the DNA sequences of the nuclear ribosomal internal transcribed spacer 1 region. SUBJECTS: Eighteen species of six genera of standard strains and 75 strains of clinically isolated Trichophyton species were used in this study. METHODS: A T. tonsurans-specific PCR primer pair (tonsF1 and tonsR1) was designed on the nuclear ribosomal internal transcribed spacer 1 region, located between 18S and 5.8S rDNA. Fungal DNA was extracted from the colonies grown on culture plates, and the specificity of the PCR primers was tested. RESULTS: The specific PCR product was amplified from the standard strain of T. tonsurans and from five strains isolated from black dot ringworms, but there was no band from the 70 clinical isolates of other Trichophyton species. This T. tonsurans-specific PCR method was able to detect 10 pg of T. tonsurans genomic DNA with ethidium bromide staining. CONCLUSIONS: A PCR identification system specific for T. tonsurans is rapid, sensitive, and specific.

DNA Probes↗

Evaluation of the effect of terpenoid quinones on Trichophyton mentagrophytes by solution and vapor contact.

The antimicrobial activity against two bacterial strains and three fungi of five terpenoid quinones, three related quinones, and a quinone-containing essential oil was investigated by broth dilution and by agar vapor and box vapor assays. All the quinones, except for coenzyme Q10, exhibited their highest activity against Trichophyton mentagrophytes. Thymoquinone showed the most potent activity, not only by solution contact but also by vapor contact, with menadione the next most potent. Alizarin showed high activity only by solution contact. The antibacterial activity was related to the orthoquinone structure (1,2-chloranil and 1,2-naphthoquinone) and the antifungal activity was related to the paraquinone structure (chloranil, ubiquinone 0, thymoquinone, and menadione).

Anthraquinones↗

In vitro antifungal activity of luliconazole against clinical isolates from patients with dermatomycoses.

The in vitro antifungal activity of luliconazole, a novel topical imidazole, against pathogenic fungi implicated in dermatomycoses was studied. A total of 91 clinical isolates, consisting of 59 Trichophyton rubrum isolates, 26 T. mentagrophytes isolates, 1 Epidermophyton floccosum isolate, and 5 Candida albicans isolates were tested by the broth microdilution method, employing lanoconazole, terbinafine, and bifonazole as reference drugs. The minimum inhibitory concentrations (MICs) of luliconazole against T. rubrum and T. mentagrophytes were in the range of 0.00012-0.004 microg/ml and 0.00024-0.002 microg/ml, respectively. The MIC90 of luliconazole for these two species of dermatophytes was the same, at 0.001 microg/ml, and these values were 4 times, 30 times, and more than 1000 times lower than those of lanoconazole, terbinafine, and bifonazole, respectively. Similarly, the 1 isolate of E. floccosum tested was inhibited by luliconazole with an MIC of 0.001 microg/ml. Luliconazole also proved to be very potent against C. albicans (MIC range, 0.031-0.25 microg/ml), nearly on par, in terms of efficacy, with lanoconazole (0.063-0.25 microg/ml) and more potent than terbinafine (2->64 microg/ml) and bifonazole (0.5-4 microg/ml). These results showed that luliconazole was very potent in vitro against pathogenic fungi isolated from patients with dermatomycoses, and these findings emphasized the utility of luliconazole for the topical management of this condition.

Antifungal Agents↗

Tween 40-based precipitate production observed on modified chromogenic agar and development of biological identification kit for Malassezia species.

We developed a simple identification kit for nine species of Malassezia (M. furfur, M. slooffiae, M. sympodialis, M. restricta, M. obtusa, M. globosa, M. pachydermatis, M. dermatis, and M. japonica) based on their biological features. This method utilizes Tween 40-based precipitate production on modified chromogenic agar (CHROMagar) Malassezia medium, growth on specific agars (Sabouraud's dextrose agar, Cremophor EL agar, Tween 60-esculin agar), and catalase reactions. This identification kit was verified with 11 type and reference strains of nine Malassezia species. An additional 26 clinical isolates were also successfully identified using the kit and the results were confirmed by molecular biological analysis.

Agar↗

The postantifungal effect (PAFE) of itraconazole, in comparison with those of miconazole and fluconazole, on Candida Species.

To study the postantifungal effect (PAFE) of itraconazole (ITCZ) against Candida species, we quantitated it using a newly introduced parameter T/C(T=time required for the drug-treated culture to reach 5-fold increase in turbidity; C=time required for the drug-free control culture to reach 5-fold increase in turbidity) referred as PAFE index and compared the results with those obtained for two other azole antifungal drugs fluconazole (FLCZ) and miconazole (MCZ). The mean values of PAFE index for ITCZ against three C. albicans strains were 1.28, 1.45, and 1.60 when exposed to the drug for 1 hr at concentrations of 1 x MIC, 2 x MIC and 4 x MIC, respectively. These values are similar to those for MCZ and appreciably higher than those for FLCZ. PAFE index values for ITCZ against each single strain of three non-albicans Candida species exposed to 2 x MIC of the drug for 1 hr were: 1.22 with C. glabrata, 1.63 with C. parapsilosis, and 3.90 with C. tropicalis. Again, comparable values were obtained for MCZ and lower values for FLCZ. The drug concentration for exposure and the duration of exposure only slightly or scarcely affected the PAFE of ITCZ, although the magnitude of the PAFE considerably varied among different strains or species tested. In general, ITCZ, as well as MCZ, produced greater extents of PAFE than those for FLCZ against C. albicans and several non-albicans Candida species.

Antifungal Agents↗

A comparative clinical study between 2 weeks of luliconazole 1% cream treatment and 4 weeks of bifonazole 1% cream treatment for tinea pedis.

The aim of the study was to compare the efficacy and safety of luliconazole 1% cream and bifonazole 1% cream as applied in the treatment of tinea pedis (interdigital-type and plantar-type). A multi-clinic, randomised single-blind, parallel group study with 34 hospitals and 11 clinics formed the study design. Five hundred and eleven patients with mycologically confirmed tinea pedis were included. Of the 489 evaluable patients, 247 were randomised to luliconazole, and 242 to bifonazole. Luliconazole 1% cream applied once a day for 2 weeks, followed by a placebo cream for 2 weeks, thereafter. Bifonazole 1% cream applied once a day for 4 weeks. Mycological effect (negative result on microscopy) and improvement of skin lesions were measured at weeks 1, 2, 3 and 4. Safety frequency and severity of adverse reactions were also measured. The improvement of skin lesions after 4 weeks was comparably good with rates of 91.5% vs. 91.7% (luliconazole vs. bifonazole). The mycological effect was characterised by high negative rates of 76.1% vs. 75.9% (luliconazole vs. bifonazole). The progression of tinea-related signs and symptom scores differed insignificantly between evaluated luliconazole and bifonazole treatment groups comprising a total of 500 patients. Both substances appeared to be comparably safe and well-tolerated.

Adult↗

Suppression of carrageenan- and collagen II-induced inflammation in mice by geranium oil.

To obtain experimental evidence on the therapeutic efficacy of essential oils in aromatherapy for inflammatory diseases, we examined the effects of geranium oil on carrageenan-induced and collagen II-induced inflammation in mice, to assess acute and chronic anti-inflammatory activities of the oil. Single intraperitoneal injection of 5 mu L of geranium oil clearly suppressed the carrageenan-induced footpaw edema and increase in tissue myeloperoxidase activity, and repeated administration of the oil suppressed collagen-induced arthritis. These results revealed that geranium oil suppressed both acute and chronic inflammatory responses in mice.

Animals↗

[Studies on the correlation of the method currently used by the Japanese Society for Medical Mycology and its modified method with the NCCLS M27-A2 microdilution method for azole susceptibility testing of Candida species].

To evaluate the currently used Japanese Society for Medical Mycology (JSMM) method for testing the azole susceptibility of yeasts, the activities of fluconazole and itraconazole were tested against recently collected clinical isolates of Candida spp. (n=946) and compared with the National Committee for Clinical Laboratory Standards (NCCLS) M27-A2 microdilution reference method. Favorable correlation with the M27-A2 method was not seen for isolates of C. albicans, C. tropicalis or other Candida spp., particularly their trailing-growth isolates. However, the degree of correlation and agreement of MIC values were markedly improved when testing was performed by the modified JSMM method in which the end-point to be read was changed from IC80 (for the current JSMM method) to IC50. These results suggest that there is an urgent need to revise the current JSMM method.

Azoles↗

A one-enzyme PCR-RFLP assay for identification of six medically important Candida species.

Early identification of Candida isolates to the species level is necessary for effective antifungal therapy, and can also facilitate control of hospital infections. Phenotype-based methods for identifying Candida species are often difficult and time-consuming. Molecular biological techniques provide a useful alternative approach. In the present study, the ITS1-5.8S-ITS2 regions of fungal rRNA genes were amplified with universal primers in 20 standard strains. Digestion of the PCR products with one restriction enzyme, MspI, allowed discrimination of medically important Candida species, including C. albicans, C. glabrata, C. parapsilosis, C. tropicalis, C. krusei, and C. guilliermondii. Using this method, we successfully identified 137 clinical isolates of Candida. Among them, C. albicans was identified as the most common species, followed by C. parapsilosis, C. tropicalis, C. glabrata, C. krusei, and C. guilliermondii. This method is a simple, rapid, and cost-effective method for differentiation between species that is applicable in clinical laboratories.

Candida↗

A novel method to estimate the contribution of the vapor activity of essential oils in agar diffusion assay.

By the combined use of agar diffusion, agar vapor and agar vapor-inhibitory assays, contribution of the vapor activity of essential oils was quantitatively estimated. The test organisms were Trichophyton mentagrophytes and Aspergillus fumigatus. Agar vapor assay was used to confirm the vapor activity of the oils. The parameter delta defined as a contribution index of the vapor activity was calculated by (1 - b-c/a-c) x 100, where a is inhibitory diameter in the diffusion assay, b is inhibitory diameter in the vapor-inhibitory assay and c is diameter of the sealed ring in the vapor-inhibitory assay (21 mm). Many of the essential oils examined showed a delta value near 100, thus providing the major contribution of the vapor activity to the inhibitory diameter. Essential oils containing aldehyde as major constituent showed low delta value, indicating the major inhibition was due to agar diffusion. Major essential oil components behaved similarly; the delta value was increased in the following order: aldehyde < phenol < alcohol < ester, oxide, hydrocarbon, indicating the enhanced contribution of the vapor activity in that order.

Agar↗

Suppression of neutrophil accumulation in mice by cutaneous application of geranium essential oil.

BACKGROUND: Previous studies suggested that essential oils suppressed the adherence response of human neutrophils in vitro and that intraperitoneal application of geranium oil suppressed the neutrophil accumulation into peritoneal cavity in vivo. Usually, essential oils are applied through skin in aromatherapy in inflammatory symptoms. The purpose of this study is to assess the effects of cutaneous application of essential oils on the accumulation of neutrophils in inflammatory sites in skin of mice. METHODS: Inflammation with accumulation of inflammatory cells was induced by injection of curdlan, a (1-->3)-beta-D-glucan in skin or peritoneal cavity of mice. Essential oils were applied cutaneously to the mice immediately and 3 hr after intradermal injection of curdlan. The skin with inflammatory lesion was cut off 6 hr after injection of curdlan, and the homogenates were used for myeloperoxidase (MPO: a marker enzyme of neutrophil granule) assay. RESULTS: The MPO activity of the skin lesion induced by curdlan was suppressed dose-dependently by cutaneous application of geranium oil. Other oils such as lavender, eucalyptus and tea tree oils also suppressed the activity, but their activities seemed weaker than geranium. Juniper oil didn't suppress the activity CONCLUSION: Cutaneous application of essential oils, especially geranium oil, can suppress the inflammatory symptoms with neutrophil accumulation and edema.

Journal Article↗

In vitro and in vivo antifungal activities of FX0685, a novel triazole antifungal agent with potent activity against fluconazole-resistant Candida albicans.

To evaluate the therapeutic potential of FX0685, a new triazole antifungal agent, for the treatment of opportunistic fungal infections, particularly systemic candidiasis and aspergillosis, in vitro and in vivo studies were performed using fluconazole (FLC), itraconazole (ITC) and/or amphotericin B (AMB) as reference drugs. A preliminary in vitro study showed that the antifungal activity of FX0685 against FLC-susceptible Candida albicans, several non-C. albicans Candida species and Cryptococcus neoformans was superior to that of FLC and comparable or superior to those of ITC and AMB, while the anti-Aspergillus fumigatus activity of FX0685 was to varying degrees lower than that of ITC. FX0685 appeared to be comparable to FLC and ITC in the treatment of murine systemic C. albicans and pulmonary A. fumigatus infection, respectively. The biological property of FX0685 was characterized by its potent in vitro and in vivo activity against FLC-resistant C. albicans. Part of this unique property was explained by the finding that it retained potent inhibitory activity against those CYP51 molecules in which amino acid substitutions confer a phenotype of resistance to FLC and some other azole derivatives. All of these results lead to the possibility that FX0685 may be a potential antifungal drug candidate for the treatment of various clinical forms of systemic candidiasis, including those caused by FLC-resistant C. albicans, as well as for the treatment of pulmonary aspergillosis.

Animals↗

Reproducible genetic transformation system for two dermatophytes, Microsporum canis and Trichophyton mentagrophytes.

A reproducible genetic transformation system was developed for two major dermatophytes, Microsporum canis and Trichophyton mentagrophytes. Two circular transformation vectors carrying either the bacterial hygromycin B phosphotransferase gene (hph) or both the hph and green fluorescent protein (eGFP) genes under the control of a promoter sequence from Cochlibolus heterostrophus were introduced independently into the protoplasts by a polyethylene glycol (PEG)-mediated method. Polymerase chain reaction (PCR) showed that the hph gene was integrated randomly into the chromosomal DNA of the transformants through non-homologous recombination. Southern blotting analysis also demonstrated a single or multiple integration of the hph gene into the chromosomal DNA. Fluorescence due to eGFP gene expression was observed in the T. mentagrophytes transformants, and the transformants retained mitotic stability through subculture. This reproducible transformation system provides a method for the genetic manipulation of these pathogens, which will facilitate detailed molecular analysis of dermatophytosis.

Blotting, Southern↗

Vital growth factors of Malassezia species on modified CHROMagar Candida.

A comparison of several media, i.e., potato dextrose agar with olive oil (Oil-PDA), modified Dixon agar (mDIX) and variations of Leeming and Notman agar (LNA) for the isolation and growth of Malassezia and Candida species was examined. Since LNA supported the highest growth of Malassezia species its key components, i.e., ox bile, glycerol monostearate, glycerol and Tween 60, were added to CHROMagar Candida. All 7 species of Malassezia grew well on this modified medium (LN-CHROM) after incubation for 4 days at 30 degrees C and development was equal to that observed on LNA. Colonies on LN-CHROM were smooth and from pink to dark purple in color. Furthermore, the use of LN-CHROM did not alter the colony characteristics of Candida species as compared to that found on CHROMagar Candida. The results of the present investigation indicate that the use of LN-CHROM would make possible the simultaneous isolation and identification of Malassezia and Candida species.

Bile↗

Effects of micafungin on the morphology of Aspergillus fumigatus.

The morphological effects of micafungin, a member of a new class of antifungal agents candins, on growing hyphae of Aspergillus fumigatus were studied by the use of Nomarski microscopy, scanning electron microscopy and thin-section electron microscopy. Micafungin at concentrations of 0.001-0.1 microg ml(-1) strongly inhibited the in vitro growth of this fungus and induced striking changes in the hyphal morphology, depending on the drug concentration and the length of the incubation period. The changes observed included increased formation of branches on the lateral walls, disruption of the tips of both hyphal cells and branches, and crushing and collapse of whole hyphae. In addition, micafungin was also effective in damaging membranous structures, including disruption of the cell membrane, partial loss of nuclear membranes and expansion of endoplasmic reticula. From these results, it was concluded that micafungin primarily affected the normal formation of cell walls and septa of growing hyphae. The inhibition of apical growth of hyphae accompanied by excessive lateral branching that was followed by disruption of both hyphal tips and branch tips ultimately led to the destruction of whole hyphae. This cytological effect of micafungin on the hyphal growth of A. fumigatus can explain its potent anti-Aspergillus activity.

Antifungal Agents↗