Basic English Grammar Module: Unit 2B. Independent Learning Resources
© Learning Centre University of Sydney. This Unit may be copied for individual student use.
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Text 2: The Research Paper
Introduction
It has been suggested (1) that lipid peroxides formed
in the arterial wall are active in atherogenesis. The
suggestion has been widely accepted as reasonable,
since these compounds break down readily, initiating
chain reactions as they do so and forming various
products that are potentially toxic. For example, lipid
peroxides denature serum -‐lipoproteins (2) and
attack the SH group of proteins (3). When vitamin E-‐
deficient rats are fed a diet rich in polyunsaturated
fats, lipid peroxides appear in their adipose and
muscular tissues (4); similarly, it is thought,
unsaturated lipids present in atherosclerotic arteries
may autoxidise and then polymerise to form "ceroid"
(5).
Lufton and Sowerby (1) provided some evidence for
the atherogenic role of lipid peroxides. They showed
that the content of peroxides in lipids extracted from
the human aortic wall increased with the degree of
atherosclerosis. They extracted the lipid, however, by
mixing the tissue exposed to the air, with anhydrous
sodium sulphate and extracting the mixture with
chloroform at room temperature. These treatments
may have caused the artifactual formation, by
oxidation, of peroxides from unsaturated lipids
during the extraction. We have therefore reopened
the question of whether lipid peroxides occur in
aorta lipids...
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