Pityrosporum ovale Modulate the Pro-inflammatory Cytokines in Normal Human Keratinocyte / 대한피부과학회지

BACKGROUNDS: Pityrosporum (P.) ovale is a member of the cutaneous microflora, and is associated with several dermatologic diseases. Little is known about the mechanism by which P. ovale causes these dermatoses, but it has been supposed to be associated with immunologic response. The epidermis is largely composed of keratinocytes, and they not only play an important structural part in forming a physical barrier to microorganisms, but also are important functionally in mediating cutaneous immune reaction by secreting various cytokines. OBJECTIVES: There have been few studies on the interaction between fungi and keratinocytes, especially the effect of P. ovale on the production of cytokines by human keratinocytes. This study is to evaluate the effects of P. ovale on pro-inflammatory cytokines such as interleukin-1alpha (IL-1alpha), tumor necrosis factor-alpha(TNF-alpha), granulocyte-macrophage colony stimulating factor (GM-CSF) producted by human keratinocytes. METHODS: Normal human keratinocytes (NHK) from neonatal foreskin were suspended in culture medium with different concentrations of the P. ovale extract (0.01, 1, 10, 100microgram/ml). The production of IL-1alpha, TNF-alpha and GM-CSF after 24 hours treatment were semiquantitated by RT-PCR. Time-course changes of the cytokines were also observed until 72 hours (0, 6, 12, 24, 48, 72 hours). NHKs were treated with P. ovale culture supernatant (0.1, 0.2, 0.5, 1.0ml) for 24 hours, and the cytokines were measured by RT-PCR and ELISA. RESULTS: IL-1alpha and GM-CSF were increased by treatment with P. ovale extract as a dose-dependent manner. But TNF-alpha production was not affected by the treatement. The level of IL-1alpha was steadily increased with its maximum at 48 hours. The level of GM-CSF was increased for 48 hours and became decreased thereafter. NHKs treated with P. ovale culture supernatant showed the increase of IL-1alpha and GM-CSF synthesis as a dose-dependent manner. CONCLUSIONS: P. ovale induced the pro-inflammatory cytokines in normal keratinocytes, which is supposed to induce inflammatory response by the organism in the skin.

Isolation of Pityrosporum ovale from a Patient with Onychomycosis: Clinical and Laboratory Investigation / 中华皮肤科杂志

Objective To isolate and observe Pityrosporum yeasts from a patient with onychomycosis. Methods The involved nail specimens were investigated by means of culture, pathological and scanning electron microscopic examination and 20% KOH preparation. Results Physical examination showed that each finger and toe nail appeared brownish black, rough and thick, some of the fore part of the nail plate detached from the nail bed. Fingernail specimen's culture results showed that Trichophyton rubrum grew on Sabouraud's dextrose agar and Pityrosporum ovale grew on the medium containing rapeseed oil. The pathological examination revealed P.ovale yeast involvement in the fissure of the nail plate. Under the scanning electron microscopy, a lot of P.ovale yeasts with characteristic collarette structure inserted in the nail tissue was noticed. In the 20% KOH preparations of nail incubated at 56℃for 1h and stained with Quink Parker ink, spores and hyphae were identified morphologically with P.ovale and T.rubrum respectively. The patient received intermittent pulse therapy with itraconazole, the color of the nails became much brighter 1 to 2 months after the fourth cycle of therapy, but no further improvement was observed afterwards. P.ovale and T.rubrum grew again 6 months after treatment when the clippings of the fingernail were cultured. Conclusion This is the first document of onychomycosis related with P.ovale in China.

Statistical and mycologic studies on dandruff / 대한피부과학회지

BACKGROUND: Previous studies suggested that Pityrosporum may play an important role in the pathogenesis of dandruff. OBJECTIVE: Our purpose was to study the statistical and mycobgic findings of dandruff in normal subjects for better understanding of this condition. MEHTODS: Scales frorn the scalp of 384 students were studied stastistically by answer sheets and clinically by a dermatologist. Mycologic studies of Pityrosporum were also performed by direct smear, culture and inoculation to guinea pigs. RESULTS: There were 76.0% subjects with dandruff. Clinically grading the subjects by Kligrnan's scale, grade III and IV(mild caling) were the most. Dandruff developed commonly at the age of 14 to 16, and no seasonal change was observed. Spores of Pityrosporum were observed in all subjects by KOH microscopic examination with Cohens method, and the grading of the dandruff was not related with the number of the spores. In most subjects, P. orbiculare and P. ovae were found together. Positive culture colonies were observed in 93.7%. Inoculation of the cultured colonies to guinea pigs resulted in an experimental dermatitis. CONCLUSION: Our study shows that Pityrosporum may involve in the pathogenesis of dandruff; however, it is still unclear whether Pityrosporum is a main causative agent of dandruff.