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C T Gregg

Publications and source records attributed to C T Gregg.

17 recordsLinked to original sources
PubMed1982

Rapid identification of microorganisms by circular-intensity differential scattering.

There is a pressing need in clinical medicine for rapid identification of microorganisms. We describe a method that has the potential for such rapid identification: circular-intensity differential scattering, which is based on the differential scattering of left and right circularly polarized light. The scanning time required to obtain the spectral signature of an organism is about 4 min. Using a commercial circular dichrograph modified to measure circular intensity differential scattering at 90 degrees, we obtained significantly different spectra for five different crude influenza viruses. Salmonella typhimurium TA98 and TA100, and Escherichia coli HB101, HB101(pBR322), and HB101(pMB9). Purified supercoiled plasmid pBR322 DNA was readily distinguishable from linear pBR322 DNA; such differences in nucleic acid packaging may be significant factors in the discriminatory power of this technique.

DNA, Bacterial↗
PubMedDate not supplied

Prenatal toxicology of shale oil retort water in mice.

Shale oil retort water, a by-product of the production of oil from shale, potentially amounts to tens of millions of gallons per year and must be treated or recycled with regard for public health. Such retort water was given to 98 female ICR/DUB mice in their drinking water at concentrations of 0, 0.1, 0.3, and 1.0% for periods up to 203 d. Seven of 75 treated animals developed adenomalike lesions that were not seen in the control animals. These ranged from adenomas and an adenomatoid nodule in the lung to the rectal adenocarcinoma. Although the incidence of adenomalike lesions was not statistically significant, this appearance of neoplasia requires further investigation. Eighty-five animals became pregnant. The proportion of animals pregnant, weights of nonpregnant animals, weight gain during pregnancy, average fetal weight, number of live fetuses per liter, and proportion of male fetuses were unaffected by drinking retort water. Early and late fetal deaths and preimplantation losses were likewise unaffected, except for a significant increase in preimplantation losses in animals consuming 1.0% retort water. A variety of palatal defects were seen in treated animals, however, including single and multiple cleft palates and a defect, to our knowledge not previously reported, in which the posterior portion of one or both palatal shelves appeared not to have formed. The palatal defects, as a group, were dose-dependent and statistically significant.

Animals↗