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Biomedical subjects

E D Shields

Publications and source records attributed to E D Shields.

11 recordsLinked to original sources
PubMed1992

Locomotory characteristics of fibroblasts within a three-dimensional collagen lattice: modulation by a helium/neon soft laser.

It has been postulated that low energy (soft) lasers can enhance wound healing. Considering the importance of cell locomotion in the wound healing process, we have studied the effects of a helium/neon laser upon the locomotory behaviour of a population of fibroblasts migrating within a three-dimensional hydrated collagen lattice. Statistical methods were used to quantify cell three-dimensional trajectories obtained using a computer-assisted tracking system. A two-minute exposure of embryonic fibroblasts to soft laser light decreased the speed and increased the frequency and duration of stops compared to controls. The locomotory phenotype induced in embryonic fibroblasts by the laser light resembled that of the developmentally older c20 fibroblasts, which are known to express a more mature locomotory phenotype. The relevance of these results to wound healing is discussed.

Animals↗
PubMed1979

Facial clefts in Danish twins.

A total of 74 Danish twin pairs with cleft lip +/- palate (CL(P)) and isolated cleft palate (CP) born in Denmark from 1941 to 1969 were studied. Eight pairs were of indeterminate zygosity status' and 26 pairs of unlike sex were dizygous (DZ). Of the remaining 42 like-sexed pairs, zygosity assignments were made from genotyping and physical resemblance data. Twelve pairs were given MZ status and thirty pairs DZ status. The following data was calculated: 1) in contrast to other reports, the incidence of either CL(P) or CP was not increased for either MZ or DZ twins; 2) using the pairwise method for concordance rate calculation, concordance rates for CL(P) twins were: MZ = 36 per cent; DZ = 1.5 per cent. For CP, MZ = 33 per cent; DZ = 0 per cent. The results support the concept that heredity is a prime factor in the etiology of clefting, but the low MZ concordance rates also suggest genetic heterogeneity in this cleft population.

Cleft Lip↗
PubMed1977

Tricho-dento-osseous syndrome: a scanning electron microscopic analysis.

A large kindred of which multiple members have the Tricho-dento-osseous syndrome is presented. This is an autosomal dominant disorder characterized by defective enamel, taurodontia, unusually curly hair and occasionally mild to moderate skeletal osteosclerosis. Histologic investigation of teeth (by both LM and SEM) demonstrated that there is a uniformly thin enamel covering with randomly distributed depression and pits. The mineral content of this enamel is closer to that of the underlying dentin, which accounts for its lack of radiographic contrast. The dentin was normal. A bizarre finding is that of a periradicular sheath or membrane that enclosed the open apices and extended partway up the root. It was composed of collagen fiber bundles. The anatomical position of this membrane suggested that it may represent the developing peridontal ligament seen in early tooth formation. Recent embryologic evidence provides support for mesenchymal culpability for all reported features of the syndrome.

Adolescent↗
PubMed1976

Allelic restriction: a biologic alternative to multifactorial threshold inheritance.

Contrary to the argument regarding the conservatism of the multifactorial threshold model for describing the inheritance of congenital malformations, little biological insight has resulted from the series of tautological, albeit grandiose, mathematical assumptions currently comprising the basis for this hypothesis. The working hypothesis of this presentation is to apply the "allelic restriction" model to the genesis of common human congenital malformations. New population data concerning isolated cleft palate closely fit the predictions of the proposed hypothesis. Recognising the heterogeneity of cleft palate as well as other common congenital malformations (namely, the difference between phenocopies, definable syndromes, and true hereditary cases), the "allelic restriction" model accords with the apparent greatly "reduced penetrance" of the heriditary cases. This model is meant to apply only to those congenital malformations which have both a high population frequency and a relatively small number of families showing an atypical type of vertical transmission.

Adult↗
PubMed1976

Periodontosis: a phenotypic and genetic analysis.

Two families who provide additional data concerning the metabolic, radiographic, and clinical parameters of periodontosis are presented. These findings include decreased serum alkaline phosphatase levels with absent liver isozyme fractions, decreased tubular bone over-all width and medullary space with relatively increased cortical area, and at least one case of primary dentition alveoloclasia with no permanent dentition alveoloclasia. In addition, a segregation analysis was performed on these two families and all completely reported families found in the literature. The results indicate that periodontosis is most probably inherited as an X-linked, dominant trait with decreased penetrance but relatively consistent gene expressivity. The female: male ratio of affected persons is approximately 2:1, and there is an over-all deficiency of males in these affected families.

Female↗
PubMed1976

Aarskog syndrome: new oral-facial findings.

The Aarskog syndrome is characterized by short stature with typical facial, digital and genital anomalies. A further case is reported which presented with the uncommon finding of ophthalmoplegia and three previously unreported oral-facial findings: enamel dysplasia, a "col" deformity of the anterior mandible and a paresis of the facial muscles innervated by the VII cranial nerve. The implications of genetic heterogeneity in this nosologic classification are discussed.

Abnormalities, Multiple↗
PubMed1975

Orofaciodigital syndrome, type I: a phenotypic and genetic analysis.

An additional family with the orofaciodigital syndrome. Type I, is presented. On the basis of previously published pedigrees, as well as the present case, data are presented that conclusively support an X-linked dominant mode of inheritance. Segregation analysis demonstrated that not only is there lethality in the male but there is significant lethality in the female due to lyonization. In addition, a review of the familial cases will demonstrate a large degree of intra- and interfamilial variation.

Abnormalities, Multiple↗
PubMedDate not supplied

Cavitation defects on the lingual ramus: a further expression of Stafne's defect.

Seven archaeological examples of 6,700 mandibles examined were found to have developmental cortical defects on the ramus. The defects, unusual in their position, were grossly and radiographically similar to developmental bone cavities (Stafne's) located in the sublingual region. Of the seven ramus defects, all of which were in adult males, six were in Alaskan Eskimos from Kodiak Island (N = 5) and Nelson Island (N = 1), and one was in a native American from Arkansas. Only five adult males from Finland have been reported with similar defects. A statistical examination of the metrics defining mandibular cavitation defects, along with prevalence data, suggest that the seemingly rare findings of ramus defects are an extreme manifestation of the continuum of severity of the Stafne's defect. Bilateral Stafne's defects also represent a severe manifestation.

Adult↗