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W R Hoffman

Publications and source records attributed to W R Hoffman.

2 recordsLinked to original sources
PubMed1990

A preliminary experience: the Ilizarov external fixator.

The Ilizarov external fixator, though developed over 35 years ago in the Soviet Union, is only now gaining popularity in the United States. Its design and versatility allow the physician to treat a wider range of limb maladies than other external fixation systems (eg, the Hoffmann device). The Ilizarov method of fixation also permits treatment of some orthopedic conditions that were previously considered to be untreatable, such as dwarfism. The device can be used to correct limb length discrepancies, manage open and closed fractures, nonunions, and bony or soft tissue deformities. A review of the first 25 cases performed at the University of Louisville revealed 15 which have been successfully completed with significant, but manageable complications, and 10 cases which are still in progress.

Adult↗
PubMed1989

Nuclear enzymes, fragile sites, and cancer.

The finding of a large number of recurrent fragile sites on human chromosomes provides suggestive evidence for the origin of recurrent chromosomal rearrangements that are a common feature in most neoplasias. These fragile sites can be induced by a wide variety of mutagens and carcinogens that are known to act through different molecular mechanisms. They correlate with two-thirds of the recurrent cancer chromosomal breakpoints known thus far and with the location of most mapped oncogenes and growth factors. Because we have now found that a large number of fragile sites can also be induced by agents such as DNase I and benzo[a]pyrene diol-epoxide (BPDE), which are known to induce hypersensitive chromatin sites, it is possible that a class of fragile sites represents regulatory regions of active genes. We have also introduced restriction enzymes into cultured lymphocytes and found that fragile sites are expressed in a pattern similar to that produced by DNase I and BPDE. Because fragile sites have a higher expression with advancing age, cigarette smoking, and deficiency of folic acid and B12 vitamins, they may represent active genomic sites that are vulnerable to physiological and environmental disturbance.

7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide↗