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J C Searls

Publications and source records attributed to J C Searls.

11 recordsLinked to original sources
PubMed1979

A comparative radioautographic study of chondrocytic proliferation in nasal septal cartilage of the 5-day-old rat, rabbit, guinea pig and beagle.

Growth sites within the cartilaginous nasal septa of four different species of animals (5-day-old rats, rabbits, guinea pigs and beagles) were identified by monitoring cellular proliferation radioautographically. A statistical analysis (MANOVA) was employed. It showed that, of the six combinations compared (rat-beagle, rat-guinea pig, rat-rabbit, beagle-guinea pig, beagle-rabbit, and guinea pig-rabbit), in only one (beagle-guinea pig) was there any similarity in growth pattern. The other five combinations all were significantly different. Since no particular areas emerged, with any consistency, as common growth sites within any of the four kinds of septa, it was concluded that the nasal septum might well play a passive role in midfacial growth, rather than an active role as previously thought.

Animals↗
PubMed1979

Quantitative characterization of changes in cellularity and collagen fiber size in contracting palatal wounds.

Standard surgical wounds with either plain or undermined margins were created in the hard palates of 15 beagle pups by excising a strip of mucoperiosteum adjacent to molars. Healing was monitored, the pups were sacrificed at intervals from five to 31 days after surgery. Longitudinal data were collected for body weight and wound contraction. Examination of histologic sections of the wounds and adjacent tissues involved visual light microscopic assessments of fibroblast population density and computerized image analysis microscopy for quantification of population densities of three sizes of collagen fibers. Wounds with undermined margins showed less contraction than did those having plain margins. Findings on changes in the morphologic character of the maturing granulation tissues included quantitative documentation of (a) decreases in the population density of fibroblasts, (b) marked decreases in the number of thin (reticular) fibers, (c) marked increases in the number of medium sized fibers, and (d) slight increases in the number of coarse fibers.

Animals↗
PubMed1976

A radioautographic study of chondrocytic proliferation in nasal septal cartilage of the prenatal rat.

Six pregnant female Sprague-Dawley rats were labeled with tritiated thymidine and killed, one each day, during the terminal six days of pregnancy. Nasal septal cartilages of five pups from each litter (a total of pups in all) were monitored radioautographically for cellular proliferation. It was found that chondrocytes were moderately active mitotically on gestational day 16, showing 12.1 grains per microscopic field. Activity increased sharply the following day (16.5 grains/field) then declined slightly on day 18 to a 16.1 count. There was a marked drop on both the 19th and 20th days (13.1 and 10.3 grains/field respectively) followed by a leveling off on the 21st day (9.3 grains/field). No specific location in the septal cartilage could be identified as a growth center. The area of highest proliferative activity varied from day to day, being seen in the nasal tip on day 16, centered in the middle two-thirds of the cartilage twenty-four hours later, then moving caudally to the posterior one-half the following day (day 18). On day 19, a final shift back to the middle of the septum was observed. It was impossible to identify an active zone anywhere within the septum of either the 20- or the 21-day prenatal rat.

Animals↗
PubMed1975

Radioautographic study of chondrocytic proliferation in nasal septal cartilage of the 5-day-old rat.

Relative rates of chondrocytic proliferation in the 5-day-old rat nasal septum are determined radioautographically, using tritiated thymidine as the labeling agent. The results are tabulated and charted graphically; they show that the zone of greatest activity is the portion just anterior to the septoethmoidal junction. The area of second highest activity is the antero-superior tip of the septum. All other regions are either relatively inactive or show only sporadic areas of proliferative activity.

Animals↗