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Biomedical subjects

P L Rubin

Publications and source records attributed to P L Rubin.

7 recordsLinked to original sources
PubMed1984

Experimental tooth ankylosis in the monkey.

In this small study, radiographs and study casts were made of three Cynamoglus monkeys with deciduous dentitions. Roots were traumatized with a chrome-steel crown in hyperocclusion, and by exposing root surfaces surgically and traumatizing with a rotating bur or chemical irritants. Histologic studies revealed scalloping resorption of cementum but no evidence of ankylosis. However, when a maxillary deciduous incisor was luxated by forceps, block sections taken four weeks after the injury revealed areas of bone in close apposition to cementum. This last type of injury would seem to be one mechanism for producing dental ankylosis in the monkey.

Alveolar Process↗
PubMed1979

Influence of trace elements and nitrogen sources on versicolorin production by a mutant strain of Aspergillus parasiticus.

A mutant strain of Aspergillus parasiticus blocked in aflatoxin biosynthesis accumulates versicolorin A and versicolorin C. The effect of trace elements on the growth and versicolorin production by this strain was studied in a defined medium. The omission of manganese was slightly stimulatory to versicolorin production; when zinc was omitted from the medium, no detectable versicolorins were produced. Experiments on nitrogen sources in a high-sucrose medium indicated that fourfold to fivefold increases in versicolorin yields could be obtained by substituting 3 ml/l corn steep liquor or 0.1 M NH4NO3 for the 0.023 M (NH4)2SO3 used previously as the nitrogen source in studies on versicolorin production by this strain. These improved yields will facilitate attempts to accumulate enough versicolorin A and versicolorin C for toxicity and carcinogenicity testing. Chromatographic profiles of mycelial extracts of cultures grown in a defined medium with 0.1 M NH4NO3 as the nitrogen source revealed 2 previously unrecognized compounds. The accumulation of these new metabolites in a mutant blocked in aflatoxin production may indicate that they are biosynthetically related to aflatoxin.

Anthraquinones↗