William George MacCallum

William George MacCallum

William George MacCallum (born April 18, 1874 in Dunnville , Ontario , † February 3, 1944 in Baltimore ) was a Canadian-American doctor and pathologist.

Life

MacCallum was the son of country doctor William A. MacCallum and his wife Florence (née Eakins). His grandfather immigrated to Dunnville from Scotland in the first half of the 19th century. MacCallum attended school and high school in Dunnville. At 15 he went to the University of Toronto and took courses in Greek and, on his father's advice, in zoology, chemistry, physics and geology. He graduated in 1894 and actually wanted to continue to study Greek. However, his father convinced him to start studying medicine. He completed an equivalent of the first year at Toronto University and then moved to the second year at the newly formed Johns Hopkins School of Medicine , where he earned his MD in 1897.

After a year internship at Johns Hopkins Hospital, he got a residency in pathology with William Henry Welch . In 1900 MacCallum went to Felix Marchand at the University of Leipzig and returned to Baltimore in 1901, where he was appointed to the professorship for pathophysiology created for him in 1908 . In 1909 he accepted a position at Columbia University , where he worked until 1917. That year he followed a call back to Johns Hopkins University, where he worked as a pathologist and director of the newly established School of Hygiene and Public Health .

In 1921 MacCallum was elected to the National Academy of Sciences .

In the winter of 1943 MacCallum fell seriously ill, so that he had to take a break in Florida . Shortly after his arrival, he suffered hemiplegia. His condition quickly deteriorated and he succumbed to his illness in February 1944.

plant

MacCallum's first significant discovery was made in 1886 in the small laboratory of his parents' house. He examined the blood of crows and found motile forms of Haemoproteus columbae , a causative agent of a malaria- like disease in birds. In further investigations he discovered the sexual reproduction of the parasite via macro- and microgamonts . He found out that the flagellum of the plasmodia, which is known but considered a degenerative form, functions like the tail of a sperm .

He made his second discovery in Leipzig while examining the lymphatic vessels of the skin of pigs. He realized that there are no pores in the endothelium of the lymph capillaries. He explained the uptake of solid particles by phagocytosis and leuco-diapedesis .

He devoted further research to the thyroid and parathyroid glands . He realized that the two organs are not functionally related and that the cramps that occur during the thyroid removal actually occur because of the parathyroid glands that were removed during the procedure. He showed that by injecting parathyroid gland material from dogs and cattle into dogs, these cramps can be stopped. In collaboration with the chemist Carl Voegtlin , he undertook experiments with calcium, sodium, magnesium and potassium. The results published in 1905 indicate that only calcium is suitable for treating such cramps. With this, MacCallum was able to prove, long before the discovery of the parathyroid hormone , that the parathyroid gland plays a decisive role in Ca homeostasis .

From 1909 MacCallum researched pyloric stenosis . He was able to show that this causes hypochloremia and alkalosis , which lead to increased excitability of the nerves and spontaneous muscle contractions . Heart valves were another area of ​​research . Through operations on dogs, he created a model for the circulatory disorders caused by heart valve stenosis and insufficiency.

literature

• WT Longcope: William George MacCallum (1874–1944) . In: NATIONAL ACADEMY BIOGRAPHICAL MEMOIRS, Vol. XXIII, pp. 337-364. ( pdF )