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Biomedical subjects

D A Keith

Publications and source records attributed to D A Keith.

At least 55 records · Page 3Linked to original sources
PubMed1981

Microsomal enzyme induction and gingival enlargement in subjects taking phenytoin.

Subjects taking the anticonvulsant phenytoin were examined for gingival enlargement and skin-fold thickness. Induced synthesis of their hepatic microsomal enzymes was estimated by measuring urinary D-glucaric acid. Gingival enlargement was positively correlated (p less than 0.05) with urinary D-glucaric acid. Although skin-fold thickness was not correlated with either urinary D-glucaric acid or gingival enlargement, mean gingival enlargement was greater in some subjects who did have an increased skin thickness than in those with normal skin thickness. The results suggest that induction of microsomal enzyme synthesis, as estimated by urinary D-glucaric acid, is related to taking phenytoin, as is gingival enlargement, and that there are other factors that affect both phenomena.

Adolescent↗
PubMed1981

New observations with routine and CT-assisted arthrography in suspected internal derangements of the temporomandibular joint.

A simplified arthrotomographic technique has been performed successfully in more than 200 patients with symptoms referable to the temporomandibular joint. Soft-tissue abnormalities not detected by plain film radiography were demonstrated. Anterior meniscus displacement was the most significant finding in patients with unilateral pain and limitation of opening. New arthrographic observations and research imaging methods, including CT-assisted arthrography, are described. Leakage of contrast material along the lateral condylar neck in patients with anterior meniscus displacement suggests associated tearing of the lateral capsular attachment. Our results confirm that arthrography is a useful diagnostic procedure for suspected internal derangements of the temporomandibular joint.

Cartilage, Articular↗
PubMed1980

The role of connective tissue in craniofacial development, function and disease.

The connective tissue, composed of cells, fibers and ground substance, plays a vital role in the processes of craniofacial development, growth, wound healing and disease. This article reviews current knowledge of connective tissue biology and relates it to certain clinical situations of relevance in oral surgery.

Amino Acids↗
PubMed1979

Phenytoin, hemorrhage, skeletal defects and vitamin K in the newborn.

The vitamin K-dependent hemostatic factors are present in reduced quantities at birth and may decrease further in the first few days of life. Administration of vitamin K1 on day 1 prevents hemorrhagic disease of the newborn. Maternal ingestion of anticonvulsants puts the newborn at greater risk from hemorrhage, possibly as a result of induction of fetal microsomal enzymes with a resultant increased oxidative degradation of vitamin K which gives rise to a vitamin K deficiency and other concomitant clinical results, for example skeletal defects. Evidence for this sequence of events is presented and the widespread effect of vitamin K deficiency on the fetus is discussed.

Abnormalities, Drug-Induced↗
PubMed1979

Phenomenon of mucous retention in the incisive canal.

Mucous glands are rarely found in the anterior palate but may be observed in the incisive canal. A case history is presented of a lesion that resembled a nasopalatine cyst both clinically and radiographically but which was in fact an intra-bony extravasation phenomenon.

Connective Tissue↗
PubMed1978

Side effects of diphenylhydantoin: a review.

For almost 40 years, diphenylhydantoin has been the preferred drug in the treatment of seizure disorders. Soon after the drug was introduced into clinical practice, gingival enlargement was noticed as a side effect and, despite much research effort, the etiology of this condition remains unknown. More recently, diphenylhydantoin-induced osteomalacia and the teratogenic effects of the drug have been reported. Recent advances in our knowledge of these conditions will be discussed and future directions for research will be outlined.

Animals↗
PubMed1977

Crosslinking profiles of elastin from anatomically defined regions of the lung.

Elastin was isolated and purified by a procedure which sequentially removed lipids, collagen, structural glycoproteins and the microfibrillar proteins. Crosslinking profiles were obtained by column chromatography either after reduction with 3[H]NaBH4 or after reaction with 14[C]NaCN and NH3. Examination of the crosslinking profiles of the elastins from various tissue regions revealed differences in the type, distribution and quality of crosslinks.

Animals↗
PubMed1977

Histologic and biochemical identification and characterization of an elastin in cartilage.

Histochemical and chemical techniques have been used to identify, isolate and characterize elastin from certain bovine cartilages. The results strongly suggest that in addition to fibroblasts and smooth muscle cells, chondroblasts also synthesize elastin. Some of the possible functions of elastin in elastic cartilages are discussed and the possiblity of a new type of elastin perhaps unique to cartilage is suggested.

Amino Acids↗
PubMed1976

Isolation, purification, and cross-linking profiles of elastin from lung and aorta.

Elastin from anatomically defined regions of young calf lung and dog aorta was isolated and purified by a procedure which sequentially removed lipids, collagen, structural glycoproteins, and the microfibrillar proteins without apparent damage to the cross-linking residues, which have been shown to be sensitive to autoclaving and hot alkali treatment. One of the methods described was effective in obtaining pure elastin from lung parenchyma. Visceral pleura was found to be the richest source (25% dry weight) of elastin in the lung tissues examined. The amino acid compositions of the elastins purified by different methods were compared for purity and for the detection of possible damage to cross-linking compounds. Cross-linking profiles were obtained by column chromatography either after reduction with 3[H]NaBH4 or after reaction with 14[C]NaCN and NH3. The 3[H]NaBH4 method, under carefully controlled conditions, proved not to be quantitatively reproducible. The reaction of elastin with 14[C]NaCN and NH3 appeared preferable due to its reproducibility; this procedure required one type of hydrolysis for the analysis of all the cross-linking compounds. Examination of the cross-linking profiles of the elastins from various tissue regions revealed differences in the type, distribution, and quality of cross-links.

Amino Acids↗