Search PubMed⌕ Search

Biomedical subjects

E Freeman

Publications and source records attributed to E Freeman.

At least 73 records · Page 4Linked to original sources
PubMed1981

Cell and virus propagation on cylindrical cellulose based microcarriers.

Microgranular DEAE-cellulose anion exchanger with exchange capacities ranging between 0-2.7 meq/gr dry materials were tested for their suitability to be used as microcarriers for culturing several anchorage-dependent-cells. It was found that cells from established cell lines (BHK, MDCK), grew as confluent monolayer on DEAE-cellulose microcarriers with exchange capacity ranging between 1.00-2.0 meq/gr dry materials. Primary cells (chick embryo fibroblast) grow as a cell-microcarriers aggregate on DEAE-cellulose microcarriers with an exchange capacity ranging between 1.59-2.0 meq/gr dry materials. Cells from human diploid cell strains grew poorly on these microcarriers. Cell yields obtained using the DEAE-cellulose microcarriers were similar to those obtained on commercially available DEAE-dextran microcarrier culturing systems. Several viruses were propagated on cells grown in DEAE-cellulose microcarrier culturing systems. Virus yields per cell were similar to those obtained in conventional monolayer cultures.

Animals↗
PubMed1980

Postsurgical bone loss following root planing by ultrasonic and hard instruments.

The ultrasonic scaler is currently used to plane the roots in periodontal surgery. The purpose of this study was to provide experimental evidence in support of, or against, the use of the ultrasonic scaler for root planning in periodontal surgical procedures. A notch was made through the enamel of each canine of nine adult cats. Full thickness mucoperiosteal flaps were elevated on each canine. Using hand curettes, soft tissue tags were removed from each tooth. At the maxillary right canines and mandibular left canines the roots were planed using the ultrasonic scaler, while at the maxillary left canines and mandibular right canines the roots were planed using hand curettes. A caliper was used to measure the distance from the notch to the crest of the alveolar process at each tooth. The mucoperiosteal flaps were repositioned and secured with cyanoacrylate cement. Three months postoperatively all 36 sites were reoperated and the distance from the notch of each canine to the crest of its alveolar process was measured using the caliper. The same caliper was used for all sites and the same investigator made all the measurements. Analysis of the results showed that all canines lost alveolar bone as a result of the surgical procedure, however, there was no statistical significance between the amount of bone lost on the canines where root planing was carried out by the ultrasonic scaler and the canines where the roots were planed with hand curettes. These findings support the use of the ultrasonic scaler for the planing of roots following elevation of mucoperisteal flaps and confirm its value in the practice of periodontal surgical procedures.

Alveolar Process↗
PubMed1978

The influence of heart rate on ouabain cardiotoxicity in cats with spinal cord transection.

The dose, serum level and ventricular content of ouabain needed to produce cardiotoxicity were examined in control cats, cats with transected spinal cords and cats with transected spinal cords whose heart rates were restored to control values by artificial pacing. The lethal dose of ouabain was higher in cats with transected spinal cords and not paced than it was in the control group. However, the lethal dose of ouabain in spinal-sectioned cats with ventricular pacing was no different from that in controls. However, in both groups of spinal-sectioned cats, death was associated with higher ventricular and serum levels of ouabain than in controls. The ventricular ouabain content of paced animals with transected spinal cords was higher than that of controls and lower than that of unpaced spinal cats. Thus, restoration of heart rate to control levels in spinal animals appeared to accelerate myocardial ouabain uptake. The lower myocardial ouabain content in the spinal-sectioned animals which were paced suggests that pacing sensitizes the heart to cardiotoxicity. Spinal section itself appears to decrease the sensitivity to ouabain partly through a decrease in cardiac rate and partly through a loss of neurogenic influence.

Animals↗
PubMed1978

The keratinization potential of crevicular epithelium: an experimental study.

Free grafts, consisting of nonkeratinized crevicular epithelium and supporting connective tissue, were placed into recipient beds prepared in nonkeratinized alveolar mucosa of the rhesus monkey. Four weeks later these grafts clinically resembled keratinized gingiva and this was confirmed by biopsy and histological examination. Electron microscopy indicated that the connective tissue supporting the crevicular epithelium changed to resemble that supporting keratinized gingiva in the 4-week graft. These findings were interpreted to indicate that crevicular epithelium has the potential to keratinize and that this potential is only realized when the inflammation is resolved in its supporting connective tissue.

Animals↗
PubMed1977

Sutural development: structure and its response to rapid expansion.

This fine structural study of the suture, its development, structure, and response to rapid expansion has shown that the sutural complex is best described in terms of the functional activity of two cell populations, namely, the osteocytic and fibrocytic series, which have the ability to remodel the tissues which they form. It is suggested that the previous detailed descriptions of differences in fiber orientation and vascular distribution reflect functional activity of a suture at any given time rather than immutable anatomic characteristics. Development of the suture and its rapid expansion showed many similarities in that growth during development and orthopedic expansion both separate the joint. If the initial inflammatory aspect of rapid expansion is ignored, the response of the suture is one of osteogenesis and fibrillogenesis, followed finally by remodeling. It is also suggested that sutural expansion involves injury followed by a proliferative repair phenomenon which, in other tissues, usually leads to the formation of scar tissue. However, the ability of sutural connective tissue fibroblasts to remodel ultimately leads to regeneration of the suture. Finally, programmed cell death has been shown to be an important feature in the development of the suture.

Activator Appliances↗
PubMed1976

The role of fibroblasts in the remodeling of periodontal ligament during physiologic tooth movement.

Our findings indicate a cellular basis for the connective tissue remodeling which takes place during physiologic tooth movement. This cell is the fibroblast which is capable of synthesizing and degrading collagen simultaneously and, utilizing this ability, the orderly control of collagen remodeling within the periodontal ligament is possible. It is suggested that this cellular basis of connective remodeling will have a direct significance for orthodontic tooth movement once control mechanisms have been established.

Amino Acids↗