Investigation of the Relationship between Invasion of Fungi and Alteration of Cell Kinetics in Hair Apparatus in Experimental Dermatophytosis, Especially in Comparison with Human Hair Fungal Infection

众所周知，实验性毛癣菌（Trichophyton，T）皮肤癣菌病在多毛动物中产生，在几周内显示自然愈合，但由T引起的人类皮肤癣菌病通常不经治疗而难以治愈。为了阐明实验性皮肤癣菌病的自然愈合过程，本研究采用湿盘法将一株须癣毛癣菌接种于豚鼠背部皮肤，并对皮损进行了连续的活检和检查。组织学上，表皮和真皮上层的炎症变化在第14天达到最大状态。大多数毛器在第16天开始缩回它们的毛球。高碘酸-希夫染色显示，感染的真菌向下侵入毛皮质的角化区，但在毛器下部周围很少有炎性细胞浸润。用BrdU染色法测定了毛囊外膜基底层和毛球中BrdU标记指数（LI）， ...更多信息 真皮和滤泡上皮在第14天显著增加。随后，BrdU-LI随着毛球回缩而逐渐降低。从这些观察结果，虽然表皮的过度增殖是实验性皮肤真菌病自然愈合的一个因素，但强烈建议真菌感染可能首先引起毛球和表皮的增殖变化，然后诱导毛球缩回和毛发脱落，导致感染真菌的完全消除。感染真菌似乎直接影响毛球中的细胞动力学。另一方面，在由各种T引起的人皮肤真菌病中，特别是当毛器官受到影响时，真菌侵入并侵入毛皮质的角质化区;然而，毛器官很少显示毛球的回缩，尽管产生的毛发变得萎缩（Arch Dermatol Res 283：233，1991）。如果假设T对动物和人类皮肤组织的组织损伤能力相同，则T感染的动物和人类毛发器官的矛盾发现可能是由于结构差异，例如毛球大小的差异，毛球中细胞动力学的差异，包括毛发周期，和/或毛球细胞对真菌毒素的耐受性差异，动物和人类之间的关系少

It is well known that the experimental Trichophyton (T) dermatophytosis produced in hairy animals shows natural healing within a few weeks, but human dermatophytosis caused by T is usually apt to be uncurable without therapy. In the present study, in order to elucidate the process of the natural healing of the experimental dermatophytosis, a strain of T mentagrophytes was inoculated in the guinea pig back skin by a wet disc method and the skin lesions were successively biopsied and examined. Histologically, inflammatory changes in the epidermis and upper dermis reached the maximal state on day 14. Most of the hair apparatus began to retract their hair bulbs on day 16. It was shown by periodic acid-Schiff staining that the infected fungi intruded down into the keratinizing zone of the hair cortex, although few inflammatory cells infiltrated around the lower part of the hair apparatus. By BrdU staining, BrdU-labeling indices (LI) in the hair bulbs as well as in the basal layrs of the epi … More dermis and follicular epithelia significantly increased on day 14. Subsequently, the BrdU-LI became lower and lower with retraction of hair bulbs. From these observations, although hyperproliferation of the epidermis is a factor for the natural healing of the experimental dermatophytosis, it is strongly suggested that fungal infection may first evoke proliferative changes in the hair bulbs as well as in the epidermis, and, then, induce retraction of the hair bulbs and falling away of hairs, resulting in complete elimination of the infectinf fungi. The infecting fungi appear to directly affect the cell kinetics in hair bulbs. On the other hand, in human dermatophytosis caused by various kinds of T,especially when the hair apparatus is affected, the fungi invade and intrude into the keratinizing zone of the hair cortex ; however, the hair apparatus seldom shows retraction of the hair bulb, although the produced hair becomes atrophic (Arch Dermatol Res 283 : 233,1991). If it is assuming that the ability of tissue injury by T is the same both in animal and human skin tissues, the contradictious findings of animal and human hair apparatus infected by T may be due to structural differences, such as difference in size of hair bulb, differences in cell kinetics in hair bulbs, including hair cycle, and/or difference in tolerance of hair bulbar cells to the poison from the fungi, between animals and human beeings. Less