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Biomedical subjects

K F Adkins

Publications and source records attributed to K F Adkins.

At least 19 recordsLinked to original sources
PubMed1993

Early cellular events in an actinomycin D-created dentin niche in the rat incisor.

Administration of actinomycin D at a dose level of 0.375 microgram/g resulted in the selective disruption of developing odontoblasts at a critical stage of morphogenesis. A dentin niche was formed which was later repaired by cellular reparative dentin. The cellular changes which resulted in dentin niche formation were studied histologically and ultrastructurally in serial longitudinal and transverse sections from tissues obtained 10 h to 80 h following injection of the drug. Five stages were identified: initial destruction (10-20 h), rapid destruction (30-40 h), debris removal (50-60 h), proliferation (60-80 h) and matrix deposition (post 80 h). The cellular changes found in the dental papilla were considerably different from those found in inflammation, resolution and repair of fibrous connective tissue. These early stages were dominated by apoptosis and heterophagy, and after 80 h by disordered dentin matrix formation. The three-dimensional morphology of the defect was reconstructed from serial sections. The shape of the niche was the result of interference by actinomycin D in the patterns of proliferation and migration of the cells in the apical region of the rat incisor tooth.

Acid Phosphatase↗
PubMed1991

Dentistry--who is in charge? Workforce and training.

The quality of dental schools and of dental education in the 1990s will continue to influence the stature of the workforce and of the profession well into the 21st century. Undergraduate and postgraduate enrollments and related recurrent funding in universities are determined by the Department of Employment, Education and Training which identifies national priority areas, particularly those with export earning potential, for preferential development. Dental schools have not benefited from these initiatives. Political agendas will be increasingly important in altering the emphasis toward education and health in the future, and leaders of the profession must actively seek greater involvement with authorities and committees which are advisory to governments.

Australia↗
PubMed1986

An histological study of cystic lesions following pulp therapy in deciduous molars.

The clinical and radiographic features of a group of apical periodontal cysts associated with endodontically treated deciduous molar teeth have been previously reported. The histological description and histochemical investigation of distinctive intraepithelial inclusions are described in this paper. The chronic inflammatory response is dominated by plasma cells and the wall contains an amorphous, eosinophilic material that is shown to contain phenolic groupings similar to those present in the intracanal medicaments used clinically. A direct relationship is proposed between the inclusions, continued antigenic stimulation within the lesions and their clinical behaviour.

Epithelium↗
PubMed1986

Pigmentary changes in rat oral mucosa following antimalarial therapy.

Pharmacogenic pigmentation of the oral mucosa has been reported following the use of a number of anti-malarial drugs. The nature and distribution of the pigment is inconclusive in the literature. The aim of the present study was to document pigment deposition within the oral mucosa of DA rats following prolonged chloroquine and pyrimethamine administration. The drugs were given as a combined dosage and separately to different groups via stomach gavage tube. After 12 weekly administrations the palatal mucosa was examined histochemically and ultrastructurally for changes in numbers and size of active melanocytes using the dopa-oxidase technique. The serum was analysed for changes in ACTH and testosterone levels. Morphometric analysis of cells incubated for dopa-oxidase showed a significant increase in the size of dopa positive cells with both drugs but an increase in the number of active melanocytes with chloroquine only. Serum levels of ACTH remained unchanged with both drugs but pyrimethamine caused an elevation in testosterone.

Adrenocorticotropic Hormone↗
PubMed1985

Aberrations in pulpal histology and dentinogenesis in transplanted erupting teeth.

Responses of pulpal tissues were assessed histologically in teeth that had been transplanted after root formation was moderately well advanced. Degeneration occurred in the coronal third, but the area was repopulated by cells proliferating from the center of the pulp. Apically, the tissues, including the odontoblasts, remained vital and functional. Widespread intrapulpal formation of osteodentin was prominent in later observation periods. Apical closure occurred prematurely by production of osteodentin and cellular cementum in the form of an apical diaphragm; these mineralized tissues were confluent with a similarly active deposition of cellular cementum apically on the root surface.

Animals↗
PubMed1984

Responses of periodontal tissues and cementum following transplantation of teeth.

Responses of periodontal tissues, particularly cementum, were assessed histologically in teeth which had been transplanted after root formation was moderately well advanced. When the epithelial root sheath persisted, it was associated with continued root formation. In instances where the sheath disintegrated prematurely, either as a consequence of the surgery or of functional factors such as occlusal forces, normal root formation did not proceed, but there was rapid and extensive production of cellular cementum apically and along the root of the tooth. A zone of imperfect cementum formation was frequently seen between the preoperative cementum and that which developed postoperatively. Dilaceration of the tip of the root, with subsequent envelopment in a bulbous mass of cementum, commonly resulted.

Animals↗
PubMed1983

Proliferation of pulpal tissues following early transplantation of developing teeth.

The responses of pulpal tissues were assessed histologically in teeth that had been transplanted as soon as crown formation was completed. The teeth were unerupted at the time of surgery and were transferred to other bony crypts, where attempts were made to reproduce their natural alignment. The pulpal tissues remained viable, although variations occurred in cellularity, vascularity and texture. There was widespread production of intrapulpal bone and osteodentine, and confluence of these tissues with proliferating apical and adjacent bone often resulted in ankylosis. The view was supported that transplanted dental tissues have a strong likelihood of surviving if the procedure is undertaken relatively early during tooth development; however, structural variations and ankylosis may compromise their subsequent value.

Animals↗
PubMed1983

Aberrations involving the enamel epithelium in transplanted developing teeth.

Structural changes that occurred when unerupted developing permanent teeth in dogs were transferred to other bony crypts or surgically prepared sockets were assessed histologically. The enamel epithelium and pieces of enamel matrix were often displaced from the developing teeth and contained within the dental sac. The epithelium underwent metaplasia, cysts frequently developed, and cementum was formed in moderate quantities when enamel matrix was directly in contact with connective tissues. Development of the crowns did not continue normally, and the teeth did not erupt.

Amelogenesis↗