Sustainable rates of sebaceous wax ester secretion were measured on the foreheads of 109 men and 167 women, aged 15-97. Each measurement was made after first depleting the cutaneous sebum reservoir by overnight absorption of lipid into a layer of bentonite clay. Lipid was then absorbed for 3 h into fresh clay in which two 2-cm cloth disks were embedded. The absorbed lipid was extracted from the disks with ether and analyzed for wax esters by thin-layer chromatography. For both men and women there was a wide range of wax ester secretion rates at all ages. Rates were highest in the 15- to 35-year-olds and appeared to decline continuously throughout the adult age range. Values of log(wax esters) were better correlated with age than the untransformed values of wax ester secretion. The equations of best fit of log(wax esters) vs age suggested that sebum secretion declines about 23% per decade in men and 32% per decade in women.
The distribution patterns of nerve fibers immunoreactive (IR) to calcitonin gene-related peptide (CGRP), substance P (SP), and neuropeptide Y (NPY) in the dental pulp, periodontal ligament (PDL), and gingiva were studied and compared with the complete innervation visualized by antibody to protein gene product (PGP) 9.5 in adult cats. The pulp showed considerably denser nerve supply for PGP 9.5, CGRP, and SP than the periodontal tissues. Most of the pulpal fibers were CGRP-IR, and approximately three to four times more IR fibers were labeled with CGRP than SP. Most fibers in the odontoblast area penetrating into the dentin tubules were CGRP-IR. NPY-IR nerves were mainly observed in connection with the larger blood vessels in pulp and PDL. In the PDL most nerves were localized in the apical third in connection with blood vessels, but CGRP-IR fibers extending close to root cementum were often observed. Immunoreactivity to PGP 9.5 and CGRP was frequently found in cell-like structures in connection with Malassez epithelium in the PDL and in some round epithelial-like cells located in the base of gingival rete pegs.
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