Macleod, John James Richard (1876–1935) Scot-
tishPhysiologist John James Richard Macleod was
bornon September 6, 1876, in Cluny, near Dunkeld,
Perthshire, Scotland, to the Rev. Robert Macleod.
Macleod went to the grammar school at Aberdeen and
later entered the Marischal College of the University of
Aberdeen to study medicine. In 1898 he worked for a
year at the Institute for Physiology at the University of
Leipzig, and the following year he was appointed
demonstrator of physiology at the London Hospital
Medical School.
In 1903 he was appointed professor of physiology
at the Western Reserve University at Cleveland, Ohio,
in the United States. In 1918 he became professor of
physiology at the University of Toronto, Canada, and
served as director of the physiological laboratory and
as an associate dean of the faculty of medicine. In 1928
he was appointed Regius professor of physiology at the
University of Aberdeen, a position he held until his
death.
For his work on the discovery of insulin with Fred-
erick BANTING, he was awarded the Nobel Prize in
physiology or medicine for 1923.
Macleod conducted research in carbohydrate
metabolism, focusing especially on diabetes, and pub-
lished some 37 papers on carbohydrate metabolism
and 12 papers on experimentally produced glycosuria
(sugar in the urine).
He wrote 11 books and monographs, including
Recent Advances in Physiology(with Sir Leonard Hill)
(1905); Physiology and Biochemistry of Modern
Medicine; Diabetes: Its Pathological Physiology
(1925); Carbohydrate Metabolism and Insulin(1926);
and the Vanuxem lectures, published in 1928 as the
Fuel of Life.He died on March 16, 1935.macroevolution Evolution that deals with large-
scale and complex changes such as the rise of species,
mass extinctions, and evolutionary trends.macromolecule Alarge molecule of high molecular
mass composed of more than 100 repeated monomers,
single chemical units of lower relative mass; a polymer.
DNA, proteins, and polysaccharides are examples of
macromolecules in living systems; a large complex
molecule formed from many simpler molecules.macrophages Blood cells that are able to ingest a
wide variety of particulate materials. They are a type of
PHAGOCYTE.magnetic circular dichroism(MCD) Ameasure-
ment of CIRCULAR DICHROISMof a material that is
induced by a magnetic field applied parallel to the
direction of the measuring light beam. Materials that
are achiral still exhibit MCD (the Faraday effect),
since the magnetic field leads to the lifting of the
degeneracy of electronic orbital and spin states and to211