Jay McLean (1890 – November 14, 1957) was an

American American(s) may refer to: * American, something of, from, or related to the United States of America, commonly known as the "United States" or "America" ** Americans, citizens and nationals of the United States of America ** American ancestry, pe ...

surgeon In modern medicine, a surgeon is a medical professional who performs surgery. Although there are different traditions in different times and places, a modern surgeon usually is also a licensed physician or received the same medical training as ...

. He is most notable for his major contribution to the discovery of

heparin Heparin, also known as unfractionated heparin (UFH), is a medication and naturally occurring glycosaminoglycan. Since heparins depend on the activity of antithrombin, they are considered anticoagulants. Specifically it is also used in the treatm ...

Early life

Born in

San Francisco San Francisco (; Spanish language, Spanish for "Francis of Assisi, Saint Francis"), officially the City and County of San Francisco, is the commercial, financial, and cultural center of Northern California. The city proper is the List of Ca ...

in 1890, he was the son of a physician, John T. McLean. McLean's family lost their home and assets in the

1906 San Francisco earthquake At 05:12 Pacific Standard Time on Wednesday, April 18, 1906, the coast of Northern California was struck by a major earthquake with an estimated moment magnitude of 7.9 and a maximum Mercalli intensity of XI (''Extreme''). High-intensity sha ...

. McLean set out to become a surgeon during his last year at Lowell High School. Following education at Lowell High School, he entered the

University of California at Berkeley The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California) is a public land-grant research university in Berkeley, California. Established in 1868 as the University of California, it is the state's first land-grant univ ...

in 1909, obtaining his Bachelor of Science degree in 1914.

Career

McLean moved to

Baltimore Baltimore ( , locally: or ) is the List of municipalities in Maryland, most populous city in the U.S. state of Maryland, fourth most populous city in the Mid-Atlantic (United States), Mid-Atlantic, and List of United States cities by popula ...

following his graduation from the

University of California The University of California (UC) is a public land-grant research university system in the U.S. state of California. The system is composed of the campuses at Berkeley, Davis, Irvine, Los Angeles, Merced, Riverside, San Diego, San Francisco, ...

before receiving an acceptance from

Johns Hopkins School of Medicine The Johns Hopkins University School of Medicine (JHUSOM) is the medical school of Johns Hopkins University, a private research university in Baltimore, Maryland. Founded in 1893, the School of Medicine shares a campus with the Johns Hopkins Hospi ...

. Following his move he was informed of a vacancy at the school and began his medical studies in 1915. McLean entered

in 1915 where he met and began work with physiologist

William Henry Howell William Henry Howell (February 20, 1860 – February 6, 1945) was an American physiologist. He pioneered the use of heparin as a blood anti-coagulant. Early life William Henry Howell was born on February 20, 1860, in Baltimore, Maryland. He gra ...

. Howell admitted McLean into his laboratory and assigned him the task of investigating if an impurity was the cause of the pro-coagulating effect of

cephalin Phosphatidylethanolamine (PE) is a class of phospholipids found in biological membranes. They are synthesized by the addition of cytidine diphosphate- ethanolamine to diglycerides, releasing cytidine monophosphate. ''S''-Adenosyl methionine can ...

or if cephalin itself had a naturally pro-coagulating effect and to compare it to other phosphatides. In 1916, when McLean was a second-year medical student, he was investigating pro-coagulant compounds when he first isolated a fat-soluble phosphatide anti-coagulant. This anti-coagulant was first isolated from the liver tissue of canines, which is how Heparin got its name(''hepar'' or "ήπαρ" is Greek for "liver"; ''hepar'' + '' -in''), first coined in 1918. Following the departure of McLean, Howell continued his work and with the assistance of T. Emmett Holt he isolated a water-soluble

polysaccharide Polysaccharides (), or polycarbohydrates, are the most abundant carbohydrates found in food. They are long chain polymeric carbohydrates composed of monosaccharide units bound together by glycosidic linkages. This carbohydrate can react with wa ...

anticoagulant. Howell also coined 'heparin' as the name of this compound despite being different from the compound previously discovered by McLean. McLean graduated from Johns Hopkins in 1919 and began an internship at the Johns Hopkins Hospital. Following completion of his internship, he began a surgical residency, in which he rotated through the Hunterian Laboratory, the laboratory founded by

Harvey Cushing Harvey Williams Cushing (April 8, 1869 – October 7, 1939) was an American neurosurgeon, pathologist, writer, and draftsman. A pioneer of brain surgery, he was the first exclusive neurosurgeon and the first person to describe Cushing's disease. ...

in 1904. McLean stayed in

until 1924 when returned to his alma-mater, the University of California to become an instructor in surgery. After three years in California, McLean took a position in the Department of Pathology at

Cornell University Cornell University is a private statutory land-grant research university based in Ithaca, New York. It is a member of the Ivy League. Founded in 1865 by Ezra Cornell and Andrew Dickson White, Cornell was founded with the intention to teach an ...

, a position which he held until 1939. After leaving Cornell, McLean moved to

Columbus, Ohio Columbus () is the state capital and the most populous city in the U.S. state of Ohio. With a 2020 census population of 905,748, it is the 14th-most populous city in the U.S., the second-most populous city in the Midwest, after Chicago, and t ...

, where he worked in private surgical practice and was appointed as an associate professor of surgery at Ohio State medical school. In 1949, he was appointed director of Radiation Therapy and Consultant in Malignant Diseases in

Savannah, Georgia Savannah ( ) is the oldest city in the U.S. state of Georgia (U.S. state), Georgia and is the county seat of Chatham County, Georgia, Chatham County. Established in 1733 on the Savannah River, the city of Savannah became the Kingdom of Great Br ...

, where he remained until his death in 1957, aged 67 years. 6 years after McLean passed away he was awarded a plaque by the

Upjohn Company The Upjohn Company was a pharmaceutical manufacturing firm founded in 1886 in Hastings, Michigan, by Dr. William E. Upjohn who was an 1875 graduate of the University of Michigan medical school. The company was originally formed to make ''friabl ...

to Johns Hopkins School of Medicine for his work in the discovery of heparin as a second-year medical student.

References

{{DEFAULTSORT:McLean, Jay 1890 births 1957 deaths American surgeons Cornell University faculty Johns Hopkins University alumni Johns Hopkins University faculty 20th-century surgeons