Endothelin and Raynaud's phenomenon
Article Abstract:
Raynaud's phenomenon refers to the abnormal constriction of peripheral blood vessels (in the hands and feet) and a decrease in blood flow in response to cold temperatures or emotion. In individuals with Raynaud's phenomenon, exposure to cold enhances platelet aggregation (clumping of blood cells involved in clotting) in peripheral blood vessels, which further restricts blood flow in the hands and feet. Prolonged restriction of blood flow can result in gangrene (tissue death). Raynaud's phenomenon can occur in conjunction with other vascular disorders such as thrombosis (formation of blood clots), and in inflammatory diseases of the skin and connective tissues such as systemic lupus erythematosus. The exact mechanism responsible for the blood vessel constriction observed in Raynaud's phenomenon is not known, but it is thought to involve factors that regulate the formation of blood clots. Recently, a peptide (protein fragment) called endothelin-1 (ET-1) was discovered. ET-1 is produced by cells that form the inner lining of blood vessels. ET-1 is a very potent constrictor of blood vessels and may play an important role in the development of vascular disorders. In order to determine if ET-1 is involved in Raynaud's phenomenon, blood flow and plasma levels of ET-1 were measured in five normal subjects and in five patients with Raynaud's phenomenon. The right hand of each subject was immersed in cold water (four degrees centigrade) for five minutes. Pulse was measured and blood samples were taken from the hand before and after exposure to cold. In the normal subjects, finger pulse (blood flow) and plasma levels of ET-1 were the same before and after exposure to cold. However, in the patients with Raynaud's phenomenon, finger pulse was greatly reduced and plasma levels of ET-1 were almost doubled after the hand was exposed to cold. It is concluded that ET-1 may be released and may cause constriction of peripheral blood vessels in response to cold temperatures in individuals with Raynaud's phenomenon. (Consumer Summary produced by Reliance Medical Information, Inc.)
Publication Name: American Journal of Medicine
Subject: Health care industry
ISSN: 0002-9343
Year: 1991
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Gone to glory
Article Abstract:
Historian John Merrington is one of the noted personalities in the modern communist movement. As a student, he was fascinated with the works of Braudel, Goubert, Ladurie and Chaunu. Merrington began to actively participate in the literary movement with the publication of the 'Zerowork' periodical during the 1970s. He died in Walthamstow in London, England on Oct 26, 1996.
Publication Name: Capital & Class
Subject: Economics
ISSN: 0309-8168
Year: 1997
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The reverend believes and achieves
Article Abstract:
The Reverend Ernestine Reems has used unconventional means to transform her crime-ridden neighborhood into a community of hope and strong religious belief.
Publication Name: Parade
Subject: News, opinion and commentary
ISSN:
Year: 2000
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