ABSTRACT
In an attempt to collect more information about the features of the vernix caseosa
(VC), a relatively unstudied material, some of the histochemical, ultrastructural,
and immunological characteristics of VC cells have been investigated. Histochemistry
and light microscopy was used to demonstrate the activity of acid and alkaline phosphatase
in VC cells, enzymes with a marked increase in activity in the amniotic fluid toward
term. Acid phosphatase activity was strongly present either as intracytoplasmic granules
or as amorphous material between the cells; alkaline phosphatase activity was absolutely
nonexistent. The ultrastructural morphology of the VC cells was analyzed by scanning
and transmission electron microscopy (TEM). Significant differences can be demonstrated
in the individual surface patterns of the VC keratinocytes. TEM showed irregularly
flattened cells in various stages of keratinization. The ultrastructural findings
confirm the dissimilarity, which exists between the individual VC cells. Finally,
immunofluorescent staining tests of frozen VC smears showed that only immunoglobulin
G conjugate gives strong positive reaction at the antigen sites of the VC cells. The
special finding in this study is the polymorph appearance of the surface pattern and
the cytoplasma structure of the VC cells, as well as the lack of uniform appearance
of the acid phosphatase activity in and between the cells. All these suggest that
the status of the individual VC cell is not similar in regard to their keratinization
and desquamation activities.
