S. Oota

Fig. 5. Legends on p. 209 (bottom).
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Mitotic LCs in the normal human epidermis

Discussion
The features of these mitotic LCs in the normal
human epidermis are the first ones observed
both by light and electron microscopy. They
seem to show actual evidence for the reproduction of LCs in the normal human epidermis. In
1979, 2 groups of investigators (Frelinger et al.,1979; Katz et al., 1979) using bone marrow
chimeric animals showed that LCs in the epidermis originated from bone marrow, and thisconcept has since been widely accepted. Thereafter, however, Czernieleski et al. (1985) using
flow cytometry showed that human epidermal
LCs were a cycling cell population in the normal (physiological) epidermis, and cited thestudy by Konrad and Hönigsmann (1973) asmorphological evidence. The present observations confirm their view. Czernielewski andDemarchez (1987) further studied the selfreproducing capacity of LCs in the human skingrafted onto the nude mouse. Thereafter,Miyauchi and Hashimoto (1989) using theATPase staining technique presented the mitotic activities of epidermal LCs in the normalmouse skin. Compared with these studies, thepresent study shows the actual features of mitotic LCs in close proximity to the natural state of
the human epidermis. In this study, the relation
between the mitosis of LCs and the kind or
osmolarity of the fixative buffer (vehicle) could
not be clarified, and the relation between themitosis of LCs and epinephrine in the local
anesthetic is also indistinct. However, it is very
interesting that the mitotic LCs in the prophasewere detected only in the materials which had
been prefixed in the fixative dissolved in
Kindaly 2 . Why so? This problem remains forfurther study.
As a whole, it must be one of the most important observations that Bibeck granules have been
witnessed in all mitotic phases of human LCs.

By the TRUS technique, it was possible forthe first time to carry out a wide survey of thehuman epidermis, to find a large amount of
mitotic LCs at the light microscopic level and toview fine details of the same cells at the electron microscopic level. Thus, anyone hereafter
can observe mitotic LCs both in the normal andpathological human epidermis, and consequently, the nature, kinetics and function of LCs canbe more clearly understood.

Acknowledgements: The author gratefully acknowledges the support of Emeritus Prof. Keiichi Tanaka andProf. Akihiro Iino, who gave him the opportunity tocarry out this study in the Second and First Depts. ofAnatomy, Faculty of Medicine, Tottori Univ.,
respectively. He further expresses his gratitude to Prof.
A. Iino for the reading of this manuscript and expresses
his appreciation to Prof. Motoyuki Mihara for the kind
help in obtaining biopsy specimens. The author also
thanks Prof. Takao Inoué and Dr. Sumire Inaga for theirheartful discussions, Dr. Tadayuki Aman for the kind
gift of dialysate, Kindaly 2, and the measurement ofbuffer (vehicle) osmolarity.

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Fig. 5 (p. 208) A: A Langerhans cell (LC) in the telophase (Fig. 1: Row 11-No. 2), × 7,000. Double arrows
indicate the process of the neighboring keratinocyte invading between the daughter LCs. Ba and b: Highmagnification photographs of the rectangular areas in A, × 21,000 and × 28,000, respectively. In the Golgi
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These show clearly the reopening of the cell function as soon as cell division is completed. Scale bar =1 µm.

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(Received September 1, Accepted September 17, 1999)

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