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Biomedical subjects

A M Lacy

Publications and source records attributed to A M Lacy.

At least 73 records · Page 4Linked to original sources

A clinical technique for bonding gold castings to teeth.

A clinical technique is presented that allows practitioners to use adhesive bonding techniques to improve the retention and seal of gold castings. At the time of delivery of a gold casting, the preparation is treated with a self-curing enamel and dentinal bonding agent. The internal surface of the casting is sandblasted and electroplated with tin to produce a surface suitable for bonding with a resin cement, which is virtually insoluble and is adhesive to both the metal surface and the treated tooth.

Acrylic Resins↗

Orientation of enzymic domains in tryptophan synthase of Neurospora crassa: an immunoblot analysis of TRP3 mutant products.

Extracts of 52 TRP3 mutants of Neurospora crassa were tested for the presence of serologically cross-reacting material by the method of electrophoretic blot analysis. The test antigen was obtained by excision of lightly stained bands of denatured pure tryptophan synthase after SDS-polyacrylamide gel electrophoresis. Rabbit antisera raised against this antigen neutralized and precipitated native tryptophan synthase. Of the 52 strains, 19 exhibited banding patterns similar to wild type on electrophoretic blots, 25 strains gave no apparent bands, and 8 strains showed unique banding patterns. This evidence and related genetic fine structure mapping data indicate that strains exhibiting banding patterns similar to wild type carry missense mutations. Strains which did not exhibit any obvious bands may have resulted from certain kinds of missense or nonsense mutations or from frameshift mutations or extended deletions. Strains exhibiting unique banding patterns on electrophoretic blots were interpreted as carrying chain-terminating mutations or deletions. Genetic fine structure mapping data place the mutant lesions of these strains in a linear order corresponding to the apparent molecular weights of the crossreacting protein fragments which they exhibit. The direction of transcription and translation of the TRP3 locus in Neurospora was inferred from these relationships. The apparent organization of the Neurospora TRP3 gene is consistent with that ascribed to the Saccharomyces TRP5 system and suggests that the N-terminal portion of the protein corresponds to the "A" protein of the Escherichia coli system and that the C-terminal portion of the protein corresponds to the "B" protein of the bacterial system.

Crosses, Genetic↗

A critical look at posterior composite restorations.

The limited serviceability of posterior composite resins relates not only to the lack of a durable composite material, but also to other factors such as postoperative sensitivity, difficulty in achieving proximal contacts, marginal leakage, and recurrent caries. However, most of the problems can be overcome by attention to materials used, selection of teeth to be restored, and clinical techniques.

Bicuspid↗