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Biomedical subjects

R S Baratz

Publications and source records attributed to R S Baratz.

5 recordsLinked to original sources
PubMed1977

Developmental changes in the protein profile of cornifying lingual epithelium.

Epithelia from the tongue dorsum of 14- to 21-day embryos, 21-day embryos, 3-week-old, and adult rats were separated from their connective tissues by incubation in balanced salt solution containing EDTA. Aliquots from total extracts of these tissues were electrophoresed on sodium dodecyl sulfate-polyacrylamide gels. Scans of gels stained with fast green (FG) revealed more than 20 peaks. Ten major peaks ranging from apparent molecular weights (MW) of 120,000 to 14,000 daltons comprised about 70% of the total protein on each gel. This report focuses primarily on two pairs of peaks, arbitrarily numbered 2 and 3 (MWs 71,000 and 69,000) and 9 and 10 (MWs 17,500 and 14,000). Peaks 9 and 10 predominated in the 15-day embryos where they comprised about 30% of the total protein. As development proceeded, there was a gradual shift in the protein profile in favor of peaks 2 and 3 until on the 20th day the relative amounts of these peaks reached a maximum and peaks 9 and 10 decreased in relative amounts. The protein profile on the 20th fetal day resembled that of the 3-week-old rats and the adults. The rise in the relative amounts of peaks 2 and 3 coincided with the morphologic appearance of large numbers of tonofilaments and the onset of cornification. When the gel was stained by a procedure specific for sulfhydryl groups, peaks 9 and 10 were especially reactive after the 18th day; plainmetric analysis revealed that these had twice the relative affinity for this stain than for FG whereas other peaks had equal or less affinity. The incorporation of [3H]cystine into peaks 9 and 10 was relatively greater than into the other proteins.

Animals↗
PubMed1976

Grid staining--a useful device.

A simple and disposable holder for electron microscope grids can be constructed from discs of silicon rubber. The discs (10 mm thick X 25 mm diameter) are scored 0.4 mm deep with a razor. Flexing the discs opens the scores for insertion of grids. Staining wells can be made from polyethylene snap-in vial tops by cutting away the nipple-like portion. After impaling the holders on the tips of a pair of forceps the grids can be washed by immersion. This holder is rigid, inert and inexpensive. It is of particular advantage for handling single-slotted grids.

Specimen Handling↗
PubMed1975

Morphogenesis of rat lingual filiform papillae.

The morphogenesis of filiform papillae on rat tongue was investigated with the electron microscope. Tongue rudiments were first seen on the 12th day of gestation. At 15-17 days, dermal papillae had formed and were arranged in hexagonal array on the dorsal lingual surface. Capping each dermal papilla was a two-layered epithelium that protruded slightly above the lingual surface, thus forming the early filiform papilla. In the next stage of development, at 18-19 days of gestation, the epithelium lining the papilla had differentiated into two cell populations, one producing hard keratin, the other producing soft keratin. Some of the keratinized epithelial cells assumed a position at an acute angle to the tongue surface and extended deep into the epithelium. In the next stage, 20-21 days, a cleft appeared within these angularly oriented cells. This resulted in the division of the epithelium into keraatin-lined individual filiform papillae. Finally, the individual papillae increased in size to the adult form.

Animals↗