Quantification of iodiconazole by LC-MS/MS, a new topical transdermal cream, in dermatophytosis patients' plasma.

BACKGROUND: A rapid and sensitive LC-MS/MS method was established to measure iodiconazole (ADKZ) in dermatophytosis patients treated topically with 2% ADKZ cream. METHODOLOGY: ADKZ was extracted by liquid-liquid extraction (LLE) and separated by an Agilent Zorbax SB-C18 column (2.1 × 150 mm, 3.5 µm) using methanol - 0.01% formic acid (70:30, v/v) as the mobile phase. All the validation assays met the acceptable criteria and the linearity ranged from 10 to 1000 pg/ml. CONCLUSION: The method has been validated to be simple, sensitive and successfully applied to the study. The average amount of ADKZ absorbed into blood was approximately 0.51 µg daily, and ADKZ blood concentrations were consistent during the four-week treatment course. The cumulation of ADKZ in vivo was almost negligible.

Higher concentration of CO2 and 37°C stabilize the less virulent opaque cell of Candida albicans.

BACKGROUND: Candida albicans (C. albicans) strains can spontaneously switch at a very low frequency from white to opaque phase. The ability to switch reversibly between white and opaque phenotype and contributes to the pathogenicity of C. albicans. White and opaque switching can be induced by various environmental signals. Previous study showed that opaque cells switch en masse to white when transferred in vitro to 37°C, the temperature of their animal host. The objective of the present study was to determine the effect of different concentration of carbon dioxide and temperature on white-opaque switching, and to determine the different anti-candida killing activity of white and opaque form by human monocyte-macrophage cell line THP-1. METHODS: White-opaque switching and opaque-white switching were assayed. Modified Lee's medium supplemented with phloxine B was used to detect white and opaque forms of C. albicans under 0.03% CO2 at 25°C, 0.03% CO2 at 37°C and 5% CO2 at 37°C. Growth curve of C. albicans was monitored using OD value at 630 nm simultaneously. White and opaque forms of C. albicans and THP-1 cells were cocultured at ratio of 1:10. Colony serial dilutions were used to assay for intracellular candidacidal activity. MTT assay was used to measure the extracellular candidacidal activity. RESULTS: Phenotype switching was successfully induced in vitro in all three strains of C. albicans. When evaluating white to opaque switching, opaque colony proportion of all colonies was 0.572 ± 0.087, 0.920 ± 0.030 and 0.985 ± 0.026 exposure of white cells to 0.03% CO2 at 25°C, 0.03% CO2 at 37°C and 5% CO2 at 37°C. When evaluating opaque to white switching, opaque colony proportion of all colonies was 0.600 ± 0.114, 0.983 ± 0.003 and 0.998 ± 0.003 exposure of white cells to 0.03% CO2 at 25°C, 0.03% CO2 at 37°C and 5% CO2 at 37°C. No significant difference of white or opaque form growth rate was found among three conditions (P > 0.05). THP-1 mediated extracellular anti-candida activity in white form was (79.80 ± 3.71)% and (56.28 ± 19.12)% at different dilution ratio, which were significantly lower than that in opaque form (100%, P < 0.01). THP-1 mediated intracellular anti-candida activity in white form ((62.98 ± 5.02)%) was significantly lower than that in opaque form ((87.07 ± 1.80)%, P < 0.01). CONCLUSIONS: Our results showed that opaque form is more vulnerable and less virulent than that in white form. It suggested that higher concentration of CO2 and 37°C in host niches stabilize the less virulent opaque cell of C. albicans, which might have implications for pathogenesis, commensalism and mating.

Primary cutaneous zygomycosis caused by rhizomucor variabilis: a new endemic zygomycosis? A case report and review of 6 cases reported from China.

We report a case of primary cutaneous zygomycosis caused by Rhizomucor variabilis and review 6 cases reported from China that share similar features and are different from those cases caused by other species of Mucorales. It is noteworthy that all 6 of the cases were observed in 3 adjacent provinces of eastern China.

Primary cutaneous zygomycosis due to Absidia corymbifera in a patient with cutaneous T cell lymphoma.

A slowly enlarging arm ulcer appeared in a 61-year-old man with cutaneous T cell lymphoma. Skin biopsy revealed aseptate hyphae and nodular small/medium-sized pleomorphic CD4(+) T cell infiltration. Cultures yielded Absidia corymbifera which was identified by phenotypic and molecular methods. Since a thorough examination did not detect organ involvement, the patient was diagnosed as having primary cutaneous zygomycosis. This is the first case report of cutaneous zygomycosis caused by A. corymbifera in a patient with primary cutaneous CD4(+) small/medium-sized pleomorphic T-cell lymphoma. Other cases of primary cutaneous zygomycosis caused by A. corymbifera are also reviewed.

Genotype comparisons of strains of Candida albicans from patients with cutaneous candidiasis and vaginal candidiasis.

BACKGROUND: It is uncertain whether genotypes of Candida albicans (C. albicans) are associated with colonizing body locations or variant conditions of infection. The aim of this study was to investigate whether there are significant associations between strain genotypes and body sites of infection and to determine the potential pathogenesis of cutaneous candidiasis at multiple locations. METHODS: A total of 151 strains of C. albicans were isolated from 74 infant patients with cutaneous candidiasis and 61 female patients with vaginal candidiasis. Patients were grouped according to the body sites and underlying conditions of infection. Genotypes were identified by polymerase chain reaction (PCR) of the 25S rDNA and PCR-restriction fragment length polymorphism (RFLP) of ALT repeats digested with EcoRI and Clal. RESULTS: Ten genotypes were detected. There were significant differences in genotype frequencies between the two groups. However, we found no clear association between genotypes and the sites of cutaneous infection or the underlying conditions of vaginal candidiasis (VVC). In addition, strains of C. albicans from multiple cutaneous locations of the same patient had identical genotypes. CONCLUSIONS: Populations of C. albicans from patients with cutaneous and vaginal candidiasis were genetically different. However, the lack of genetic difference between strains from different body sites with cutaneous infections or from different underlying conditions for VVC suggests no evidence of genotype selection for different skin surfaces or patients with different underlying conditions for VVC.

[Effects of Malassezia isolates on cytokines production associated with melanogenesis by keratinocytes].

OBJECTIVE: To investigate the co-culture of keratinocytes with Malassezia isolates which cause the pityriasis versicolor with different color and to analyze the changes of cytokines associated with melanogenesis. METHODS: The effects of Malassezia species with different proportions on the growth rate of keratinocytes was assessed with 5 g/L methyl thiazolyl tetrazolium (MTT). Co-culture of keratinocytes and Malassezia species were performed with isolates from hyer- and hypo-pigmentation areas of pityriasis versicolor. The supernatants were collected at different time points, and the changes of basic fibroblast growth factor (b-FGF), endothelin-1 (ET-1), nerve growth factor-beta (NGF-beta), interleukin-1alpha (IL-1alpha), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), stem cell factor (SCF) were recorded. Three control groups were established accordingly. RESULTS: When the ratio between keratinocytes and Malassezia species was lower than 1: 10, the growth rate of keratinocytes was not affected by Malassezia (P > 0.05). When the ratio was increased above 1:20, the growth rate of keratinocytes was significantly inhibited by Malassezia (P < 0.01). The secretions of IL-1alpha, IL-6, TNF-alpha, and ET-1 was significantly increased after the co-culture of keratinocytes and Malassezia (P < 0.01), while those of b-FGF, NGF-beta, and SCF had no significant changes (P > 0.05). Compared with the isolates from the hypo-pigmentation area, ET-1 induced by isolate from hyperpigmentation area significantly increased (P < 0.01). CONCLUSION: When Malassezia isolates are co-cultured with keratinocytes, the secretions of cytokines associated with melanogenesis may differ from each other. ET-1 may play certain role in the hyper-pigmentation of pityriasis versicolor.