Glycated hemoglobin is a form of hemoglobin, chemically linked to a sugar. Most monosaccharides, including glucose and fructose, spontaneously bind with hemoglobin, when present in the bloodstream of humans. However, glucose is less to do so than galactose and fructose, which may explain why glucose is used as the primary metabolic fuel in humans; the formation of the sugar-Hb linkage indicates the presence of excessive sugar in the bloodstream indicative of diabetes. A1C is of particular interest; the process by which sugars attach to Hb is called glycation. HbA1c is a measure of the beta-N-1-deoxy fructosyl component of hemoglobin, it is measured to determine the three-month average blood sugar level and can be used as a diagnostic test for diabetes mellitus and as an assessment test for glycemic control in people with diabetes. The test is limited to a three-month average because the average lifespan of a red blood cell is four months. Since individual red blood cells have varying lifespans, the test is used as a limited measure of three months.
Normal levels of glucose produce a normal amount of glycated hemoglobin. As the average amount of plasma glucose increases, the fraction of glycated hemoglobin increases in a predictable way. In diabetes, higher amounts of glycated hemoglobin, indicating poorer control of blood glucose levels, have been associated with cardiovascular disease, nephropathy and retinopathy. Glycated hemoglobin is preferred over glycosylated hemoglobin to reflect the correct process. Early literature used glycosylated as it was unclear which process was involved until further research was performed; the terms are still sometimes used interchangeably in English language literature. The naming of HbA1c derives from Hemoglobin type A being separated on cation exchange chromatography; the first fraction to separate considered to be pure Hemoglobin A, was designated HbA0, the following fractions were designated HbA1a, HbA1b, HbA1c, in their order of elution. Improved separation techniques have subsequently led to the isolation of more subfractions.
Hemoglobin A1c was first separated from other forms of hemoglobin by Huisman and Meyering in 1958 using a chromatographic column. It was first characterized as a glycoprotein by Bookchin and Gallop in 1968, its increase in diabetes was first described in 1969 by Samuel al.. The reactions leading to its formation were characterized by Bunn and his coworkers in 1975; the use of hemoglobin A1c for monitoring the degree of control of glucose metabolism in diabetic patients was proposed in 1976 by Anthony Cerami, Ronald Koenig and coworkers. Glycated hemoglobin causes an increase of reactive free radicals inside blood cells. Radicals alter blood cell membrane properties; this leads to blood cell aggregation and increased blood viscosity, which results in impaired blood flow. Another way glycated Hb causes damage is via inflammation, which results in atherosclerotic plaque formation. Free-radical build-up promotes the excitation of Fe2+-Hb through Fe3+-Hb into abnormal ferryl Hb. Fe4 + reacts with specific amino acids in Hb to regain its Fe3 + oxidation state.
Hb molecules clump together via cross-linking reactions,and these Hb clumps promote cell damage and the release of Fe4+-Hb into the matrix of innermost layers of arteries and veins. This results in increased permeability of interior surface of blood vessels and production of pro-inflammatory monocyte adhesion proteins, which promote macrophage accumulation in blood vessel surfaces leading to harmful plaques in these vessels. Glycated Hb-AGEs go through vascular smooth muscle layer and inactivate acetylcholine-induced endothelium-dependent relaxation through binding to nitric oxide, preventing its normal function. NO is a potent vasodilator and inhibits formation of plaque-promoting LDLs oxidized form; this overall degradation of blood cells releases heme from them. Loose heme can cause oxidation of LDL proteins, which results in plaques. Glycation of proteins is a frequent occurrence, but in the case of hemoglobin, a nonenzymatic condensation reaction occurs between glucose and the N-end of the beta chain.
This reaction produces a Schiff base, itself converted to 1-deoxyfructose. This second conversion is an example of an Amadori rearrangement; when blood glucose levels are high, glucose molecules attach to the hemoglobin in red blood cells. The longer hyperglycemia occurs in blood, the more glucose binds to hemoglobin in the red blood cells and the higher the glycated hemoglobin. Once a hemoglobin molecule is glycated, it remains that way. A buildup of glycated hemoglobin within the red cell, reflects the average level of glucose to which the cell has been exposed during its life-cycle. Measuring glycated hemoglobin assesses the effectiveness of therapy by monitoring long-term serum glucose regulation. A1c is a weighted average of blood glucose levels during the life of the red blood cells. Therefore, glucose levels on days nearer to the test contribute more to the level of A1c than the levels in days further from the test; this is supported by data from clinical practice showing that HbA1c levels improved after 20 days from start or intensification of glucose-lowering treatment.
Several techniques are used to measure hemoglobin A1c. Laboratories use high-performan
R. C. T. Lee known as Richard C. T. Lee, received his B. Sc. degree from the Department of Electrical Engineering of National Taiwan University and Ph. D. degree from the Department of Electrical Engineering and Computer Science from University of California, Berkeley. He worked for NCR from 1963 to 1964 after he got his M. S. degree. After getting his Ph. D. degree, he joined National Institutes of Health, Maryland in 1967 and worked in Naval Research Laboratory, Washington, D. C. in 1974. He returned to Taiwan in 1975 and started his teaching career in National Tsing Hua University, Taiwan. In this university, he had been the chairperson of Department of Computer Science and Department of Electrical Engineering. In 1984, after he became the Dean of College of Engineering and in 1988, he was appointed as the Provost. In 1994, he was the Acting President of National Tsing Hua University. From 1994 to 1999, he was the President of Providence University in Shalu, Taiwan and in 1999, he was the President of National Chi Nan University, Taiwan.
He is now a professor of Chi Nan University under the joint appointment of four departments: the Department of Computer Science, the Department of Information Management, the Department of Communication and the Department of Medical Science. Professor Lee has published 80 papers, all in prestigious academic journals, he has been editors for ten journals. In 1989, he became an IEEE fellow, he received the Distinguished Research Awards from the National Science Council, Republic of China, five times and the Ministry of Education Engineering Academic Achievement Award in 1989. He is a Micronix Chair Professor. Professor Lee and R. C. Chang coauthored the book “Symbolic Logic and Mechanical Theorem Proving”, published by Academic Press in 1973; this book was translated into Japanese and Italian. In 2005, McGraw-Hill published his “Introduction to the Design and Analysis of Algorithms, a Strategic Approach”, which he coauthored with S. S. Tseng, R. C. Chang and Y. T. Tsai. In addition to publishing technical papers, Professor Lee has been an author of short stories.
His four books, “Let the Wall Come Down”, “The Stranger”, “The Curtain Never Falls” and “The Bell Rings Again” have been all popular in Taiwan. “Let the Wall Come Down” has been sold more than 300,000 copies within a short period of seven years. He published a book advising young people to pay attention to basics, entitled “Let Us Go Back to Basics”. Lee is a professor of both the Computer Science and Information Engineering Department and Information Management Department of National Chi Nan University. Professor Lee is an IEEE fellow, he co-authored Symbolic Logic and Mechanical Theorem Proving, translated into Japanese and Italian. Employment: 1. Engineer, National Cash Register Company, U. S. A. 1962–1963. 2. Senior Research Fellow, Occupational Safety and Health Administration, U. S. Department of Labor, October 1967 – June, 1974. 3. Research Fellow, Research Institute of U. S. A. Navy, Aug. 1974 – August 1975. 4. Chairman, Institute of Applied Mathematics, National Tsing Hua University, August 1975 – July 1977.
5. Chairman, Institute of Computer Management, National Tsing Hua University, August 1977 – July 1983. 6. Chairman, Department of Electronic Engineering, National Tsing Hua University, August 1983 – July 1984. 7. Dean, College of Engineering, National Tsing Hua University, August 1984 – July 1988. 8. Provost and Acting President, National Tsing Hua University, August 1988 – January 1994. 9. President, Providence University, February 1994 – June 1999. 10. President, National Chi Nan University, July 1999 – November 1999. 11. Professor, Department of Computer Science and Information Engineering, National Chi Nan University, December 1999 – Present. Academic Awards: 1. 1989: IEEE Fellow. 2. Distinguished Research Awards of the National Science Council of the R. O. C. 1989-1993. 3. Academic Engineering Research Award of Ministry of Education of the R. O. C. 1989. 4. Outstanding Research Award of the Hou Jin-Dui Foundation, 1993. 5. 1995 TECO Technology Award of the TECO Technology Foundation, 1995. 6. Distinguished Research Fellow of National Science Council of the R.
O. C. Since 1986. 7. Medal of Honor of the Institute of Information and Computing Machinery, 2001. 8. Chair Professor of Macronix International Co. Ltd, Since 2001. 9. Heritage Prize of The Phi Tau Phi Scholastic Honor Society of the R. O. C. 2004. 10. Honorary Doctorate Degree, ed Ph. D. Christian Chung Yuan University, Taiwan, 2005. 11. Second Class Economics Medal of Honor from the Ministry of Economics Affairs, 2005. "Let the Wall Come Down", by Linkingbooks Press. "The Stranger", by Linkingbooks Press. "The Curtain Never Falls", by Futurebooks Press. "The Bell Rings Again", by Linkingbooks Press. "The Basic English Grammar for Chinese ", by Linkingbooks Press. "Let Us Go Back to Basics", by Yuan Sun Press. Lee, R. C. T. Shen, C. W. and Chang, S. C. 1982, Compilers, in “Handbook of Software Engineering”, Van Nostrand Reinhold, N. Y. pp. 201–233. Lee, R. C. T. 1981, Clustering Analysis and its Applications, in “Advances in Information System Science”, Plenum Press, N. Y. pp. 169–287. Introduction to the Design and Analysis of Algorithms Symbolic Logic and Mechanical Theorem Proving R. C. T. Lee home page Talk Given at Rice University on September 15, 2000
Herman Brood & His Wild Romance is an export album by Dutch rock and roll and blues group Herman Brood & His Wild Romance. Released only in the United States, it contained most of the songs from his second studio album, Shpritsz; the main differences between the two albums were omission of the song "One" modified times and track order, the U. S. single version of "Saturday Night". The album was a moderate success; as a result, Brood sought to open up the American market, recording the follow-up, Go Nutz, in the US. Herman Brood - piano, vocals Freddy Cavalli - bass Danny Lademacher - guitar Cees Meerman - drums Peter Walrecht - voormalig drummer