Multimedia is widely used in dermatology teaching.Some problems are analyzed in this article,such as the problem of communication between teachers and students,teaching contents,teaching methods and multimedia making.Methods to solve these problems are also suggested.

Objective To rapidly detect and identify pathogenic fungi of some deep fungal infections by PCR.Methods The suspensions of22pathogenic fungi(23strains)were amplified by PCR with fungal universal primers ITS86and ITS4which were labeled by FAM.The precise length of amplified fragments was determined by ABI PRISM TM 377Sequencer and Genescan analysis software,then compared with that of am-plicons of corresponding fungal DNA which were previously extracted.Results(1)Amplification of17pathogenic fungi with ITS4,ITS86resulted in a unique fragment length(except for A.nidulans and A.niger,C.albicans and C.stellatoidea,F.pedrosoi and E.dermatitidis).(2)No significant difference of the length of am-plicons was found between the fungal suspension and control organisms,based on the results of Genescan analysis.(3)The whole process took only6h to complete the detection.Conclusion The combination of fun-gal suspension PCR with ITS fungal universal primers and Genescan analysis might provide an accurate,spe-cific,sensitive,and rapid approach to detect and identify22pathogenic fungi causing deep fungal infections,and hold promise to be applied for the diagnosis of deep fungal infection.

Objective To investigate the regulatory effect of calcitonin gene-related peptide (CGRP) on the mRNA and protein expression of neuronal nitric oxide synthase (NOS), as well as the release of nitric oxide (NO) in cultured human keratinocyte line HaCaT. Methods NO level in the supernatant of cell culture medium was detected with an enzymatic NO detecting kit, the mRNA expression of neuronal NOS was studied with reverse transcription polymerase chain reaction(RT-PCR), and the protein expression of neuronal NOS was studied with immunochemical technique(SP). Results Compared with that in normal culture condition, the mRNA and protein expression of neuronal NOS and the release of NO was significantly upregulated by CGRP in HaCaT cells. Whereas, the expression of neuronal NOS and the release of NO in HaCaT cells induced by CGRP was inhibited by CGRP-8-37, an inhibitor of CGRP receptor. Conclusion The expression of neuronal NOS in keratinocytes and the release of NO from keratinocytes could be upregulated by CGRP.

Objective To investigate the expression of IL-8 and CXCR2 on keratinocytes from psoriatic lesions and their roles on clinical and pathologic manifestations. Methods The chemotaxis of psoriatic lesional keratinocytes was detected by micropore loculus test. The concentration of IL-8 was determined in the cultured supernatants of psoriatic keratinocytes by ELISA. The expression of CXCR2 on keratinocytes from affected skin was tested by flow cytometry. Results The chemotaxis for neutrophils by the cultured supernatants of psoriatic lesional keratinocytes was significantly stronger than that by controls. The concentration of IL-8 in the cultured supernatants of psoriatic lesional keratinocytes was also increased. The expression of CXCR2 on psoriatic keratinocytes was significantly increased. Conclusions The psoriatic epidermal hyperproliferation may be correlated with up regulation of IL-8 production and CXCR2 expression on psoriatic keratinocytes. At the same time, the psoriatic inflammation may be partly related to the increase of secretion of IL-8, which has chemotactic capacity, by keratinocytes. IL-8 and CXCR2 may be involved in the pathogenesis of psoriasis.

Objective:To investigate the clinical infection status and trends in drug resistance of a rare pathogen Kluyveromyces marxianus ( Candida kefyr), and to provide experience for clinical diagnosis and treatment. Methods:Morphological and molecular biological identification tests and in vitro microdilution drug susceptibility test were conducted on a Kluyveromyces marxianus strain recently isolated from the midstream urine sample of a patient with urinary calculus in the Fungal Laboratory, Changhai Hospital. The ultrastructural damage of the strain caused by different antifungal drugs was observed by scanning electron microscopy. A retrospective analysis was conducted on clinical cases of Kluyveromyces marxianus infection in Changhai Hospital from 2009 to 2021. Results:The isolated strain formed smooth, soft, cheese-like yeast colonies on the Sabouraud′s agar medium, and ovoid or slender spores were observed under the microscope. Morphological analysis, mass spectrometry and sequencing analysis identified the strain as Kluyveromyces marxianus. The drug susceptibility test showed that minimum inhibitory concentrations (MICs) of amphotericin B, fluconazole, itraconazole, voriconazole, posaconazole, flucytosine, caspofungin, and micafungin were 0.5, 0.5, 0.03, ≤ 0.03, 0.06, 0.5, ≤ 0.016, and 0.06 μg/ml, respectively. Under the scanning electron microscope, the strain was ovoid to slender before antifungal drug treatment, with a size of (3.0 - 6.5) μm × (5.5 - 11.0) μm; after 24-hour treatment with antifungal drugs at the dose of 1 μg/ml, cell membrane shrinkage was more obvious under the treatment with posaconazole, which exhibited a stronger destructive effect on the strain compared with amphotericin B and voriconazole. From 2009 to 2021, 8 cases of Kluyveromyces marxianus infection were collected, including 6 males and 2 females; the Kluyveromyces marxianus strains were isolated from ascites in 3 cases, bronchoalveolar lavage fluid in 1 case, sputum in 2 cases, and midstream urine samples in 2 cases. Conclusion:For suspected Kluyveromyces marxianus infection, it is crucial to determine the pathogenic species as early as possible using various identification methods, and to collect strain as well as evaluate drug susceptibility, which will be beneficial for targeted clinical treatment.