Two rare and dominant mutants of Chinese hamster ovary (CHO) cells, LEC11 and LEC12, express the mouse embryonic antigen SSEA-1. Parental CHO cells and the revertants, LEC11.R9 and LEC12.R10, do not express this antigen as detected by a sensitive radioimmunoassay with a monoclonal antibody to SSEA-1. The presence of the SSEA-1 determinant correlates with the apparent de novo expression of specific N-acetylglucosaminide alpha(1,3)fucosyltransferase activities not detected in parental or revertant cell extracts. Several differences in the enzymes substrate specificities and their products have been identified. The combined data suggest that LEC11 and LEC12 mutants result from regulatory mutations affecting different fucosyltransferase genes.

Amino Sugars↗

PubMed1983

Copper and zinc levels in the blood of thoroughbreds in training in the United Kingdom.

The concentration of copper and zinc in the blood and sera of over 300 Thoroughbreds in training was determined by atomic absorption between February 1979 and July 1981. The mean (+/- sd) concentration of copper in the serum of stabled Thoroughbreds (79 +/- 16 micrograms/dl) was significantly (P less than 0.0001) lower than that of those at grass (101 +/- 26 micrograms/dl), whereas the mean serum zinc concentration of stabled Thoroughbreds (170 +/- 54 micrograms/dl) was higher than that of those at grass (111 +/- 45 micrograms/dl). No such differences were observed in whole blood. There were marked differences in the mean serum copper and zinc concentrations in the blood of Thoroughbreds housed in different stables. Significant changes occurred throughout the year in the mean values from individual stables. However, there were no such changes in the mean values of the total population. The observed differences were probably caused by dietary variations. The results emphasise the need to establish reference values related to diet if copper and zinc levels in blood are to be used for interpretative purposes.

Animals↗

PubMed1983

Progressive chloroquine retinopathy.

Chloroquine retinopathy is a well-documented toxic manifestation of a commonly used systemic medication. The major retinal findings are those of macular retinal pigment epithelial changes, narrowed retinal vessels, and scotomatous visual field defects. The fluorescein angiographic findings are those of a retinal pigment epithelial transmission defect that takes on a bull's-eye configuration. We present a patient who had taken chloroquine for two years while in the military service. Two years after discharge, he was examined and reported to have a mild granular appearance to the macula. Over a period of nine years, progressive decreased central acuity prompted repeated fluorescein angiograms, which revealed a progressive bull's-eye maculopathy compatible with chloroquine retinopathy. Evaluation of offspring failed to reveal any evidence of a hereditary macular dystrophy. To our knowledge, this is the first reported case of delayed onset and progression of chloroquine maculopathy documented by fluorescein angiography.

Chloroquine↗

PubMed1982