Ormond G. Mitchell

Nerve growth factor in skeletal tissues of the embryonic chick

SummaryThis study demonstrates, via immunohistochemistry and bioassay, the presence of NGF in embryonic bone and cartilage of the chick. Embryos were killed on days 6–9 of incubation at 12 h intervals, and on days 10–18 at 24 h intervals. Paraffin-embedded sections of hind limbs or buds were immunostained with a polyclonal antibody against NGF and the biotin-avidin-horseradish peroxidase technique. Immunostaining was positive in both bone and cartilage, with cartilage staining more intensely. For bioassay, bones from the hind limbs of 9- and 12-day embryos were fast-frozen, lyophilized, and homogenized with Medium 199 (M199). Dorsal root ganglia from 8-day embryos were cultured for 24–36 h with rooster plasma, M199, and varying concentrations of bone homogenate. Significant neurite outgrowth was seen, with the greatest response elicited by 12-day bone homogenate. Addition of anti-NGF to the cultures abolished neurite outgrowth. The results indicate that NGF is present in cartilage and bone of the chick embryo; it may determine the density of sympathetic innervation to the developing skeletal tissues.

Effect of Castration and Transplantation on Ventral Gland of the Gerbil.

Summary The male gerbil has a mid-ventral gland composed of specialized sebaceous gland units associated with hair follicles. This gland hypertrophies and becomes active at the onset of sexual maturity. In the adult male, the gland is a slightly elevated orange fusiform pad in the mid-ventral line and averages 22.2 mm × 7.4 mm in length and width. The gland functions equally well when transplanted to another site of the body. Castration causes the gland to involute. However, this is reversible by administration of testosterone. The sebaceous glands of the mid-ventral skin of the gerbil are androgen sensitive.

Structure and Secretory Mechanism of Rodent and Primate Palatine Glands

Receise I for phblic.ties Anugost 24, 1966. Where histologic observations were made, biopsy samples taken from animals anesthetized with pentobarbital sodium were fixed in aceto-alcohol-formalin or Zenkers fluid and stained with hematoxylin and eosin, Mallorys connective tissue stain, or mucicarmine. The mechanisms of secretion were studied while viewing the palate with a dissecting microscope. The effects of drying the surface of the palate or rinsing it with an astringent (0.2 percent zinc chloride solution) were studied in animals lightly anesthetized with pentobarbital sodium to learn what would induce secretion of the palatine glands. To see if the mucous reflex action could be inhibited, 0.01 mg. of atropine sulfate in 0.1 ml. normal saline solution was injected intraperitoneally into the hamsters soon after the anesthetic was introduced.

Cytomegalovirus in the Submandibular and Sublingual Glands of the Southern Grasshopper Mouse (Onychomys torridus torridus)

The infection observed within the submandibular and sublingual glands of the grasshopper mouse, Onychomys torridus torridus, is a cytoinegalovirus.

Effect of dentures and astringents on palatal mucosa

Abstract Continued covering of the surface of the palate results in a progressive regression of the palatal glands. Astringents initiate activity of the glands. Frequent removal of any restoration and rinsing will keep the mucous membrane in a better physiologic state. Rinsing the mouth with an astringent reflexly stimulates palatal glandular activity. This activity and dilation of the ducts cause turgidity within the adjacent tissues. This intrinsic pressure induces a smooth surface of the mucous membrane for the making of an impression.