Thursday, March 19, 2020
Cholesterol The Good and Bad Essays
Cholesterol The Good and Bad Essays Cholesterol The Good and Bad Paper Cholesterol The Good and Bad Paper Cholesterol The Good and Bad Cholesterol is the principal sterol for animals and humans alike, consisting of a hydroxyl group, a steroid group, and a hydrocarbon side chain. (htpp://EncyclopediaBritannica.com). It is an insoluble lipid substance produced by the liver and found both in cell membranes and circulating in the blood stream. The name cholesterol is derived from the Greek word chole, which means bile, in conjunction with stereos, also a Greek word that means solid. That is because it was discovered in the 18th century in solid form, as gallstones, by Franà §ois Poulletier de la Salle in 1769. The -ol part in the word is the way alcohol is named in chemistry.  A few years later the chemist Eugà ¨ne Chevreul gave it the name cholesterine. (htpp://EncyclopediaBritannica.com). Cholesterol was correctly synthesized for the first time in 1951 by Robert B. Woodward, an American chemist and Nobel Prize winner, and it has been known to have potentially dangerous health effects as early as the year 1910 (http://science.jrank.org/pages/1454/Cholesterol-History.html) On that year, Russian biologist Nikolai Antischow found plaques of cholesterol on the arterial walls of laboratory rabbits fed a high cholesterol diet. This breakthrough discovery prompted scientists around the world to further study the controversial and elusive role of cholesterol and its relation to heart disease, currently the leader in deaths for both men and women in the Western world. That’s because even though cholesterol is involved in many important metabolic processes, there has been increasingly clear evidence that when present in elevated levels it can lead to Cardiovascular Disease (CVD), stroke, and atherosclerosis. Cholesterol, contrary to its popular image as a potent enemy of health and longevity, is actually a crucial substance that performs innumerable vital functions in the body. Cholesterol is needed for the synthesis of bile acids, which are essential for the absorption of fats, and of many hormones such as testosterone, estrogen, dihydroepiandrosterone, progesterone, and cortisol. Together with sun exposure, cholesterol is required to produce vitamin D. Cholesterol is an essential element of cell membranes, where it provides structural support and may even serve as a protective antioxidant. (Colpo 83) Cholesterol levels are measured in milligrams per deciliter of blood. The desirable levels are 200 mg/dL, while anything over 239 mg/dL is considered high. The imminent connection between CVD and elevated levels of blood cholesterol is that as excessive amounts circulate freely in the blood stream, it accumulates in the arterial walls. When this process continues over the years, the buildup, also called plaque, hardens and therefore narrows the arteries. Calpo mentions that:        The plaques are complex entities with numerous        components, including smooth muscle cells, calcium,        connective tissue, white blood cells, cholesterol,        and fatty acids (84). The result is a reduced volume of blood reaching the heart; blood that is rich in oxygen necessary for its normal function. A heart attack occurs when an artery gets completely blocked. Of particular importance is the Framingham Heart Study started in 1948 under the direction of the National Heart, Lung, and Blood Institute and the University of Boston. Culminating in 2005 and spanning three generations of thousands of people, it conclusively catalogs hypercholesterolemia as a risk for CVD and other serious health conditions. This study spawned over 1,200 medical research articles published in leading medical journals (Byrne). Still under investigation by the Framingham Heart Study is the direct relationship of low density lipoproteins (LDL), commonly known as â€Å"bad cholesterol†and CVD (framingham.com/heart/). There is mounting evidence that low density lipoproteins (LDL) and high density lipoproteins (HDL) play an important role in the overall health effects of cholesterol:            Because cholesterol is water-insoluble, it must be transported inside lipoproteins. Various types of lipoproteins exist, but the two most abundant are low-density lipoprotein (LDL) and high-density lipoprotein (HDL). The main function of LDL is to transport cholesterol from the liver to tissues that incorporate it into cell membranes. HDL carries old cholesterol that has been discarded by cells back to the liver for recycling or excretion.(Colpo 83) Based on this information, HDL is considered a benign type of cholesterol, while LDL is feared as the main culprit of increasing the incidence of a large variety of cardiovascular ailments. Optimal LDL levels are 100 mg/dL, and anything over 159 mg/dL is considered high, placing the patient at risk of CVD. On the other hand, because HDL is a type of cholesterol that could prevent heart disease, the higher its levels the better for the patient. Thus, doctors look for numbers at around 60 mg/dL, while blood test results lower than 40 mg/dL might place the patient at an elevated risk of heart disease. Furthermore, there is clear evidence that genetics plays a role in hypercholesterolemia:           The cells of the body contain information, in the form of genes, for the body to make all the necessary structural components and chemicals to ensure normal function. Genes contain the instructions for the way in which cholesterol and other fats are taken into the cells. The LDLR gene contains the instructions for the body to make the low-density lipoprotein (LDL) â€Å"receptor†           (R) that enables the absorption of the LDL into the cell. When this receptor            is not working properly, cholesterol and other fats build-up in the blood,            causing plaques to form and resulting in a susceptibility (predisposition) to            coronary artery disease. (McKusick 298) While McKusick concludes that a very small percentage of the population carries the faulty gene, scientists have been able to confirm that age and gender also play a role in cholesterol levels found in the general population (299). Middle-aged men and women typically notice their cholesterol levels rise, and even though pre-menopausal women maintain lower numbers than men, once they reach menopause their numbers are equal to men. Moreover, most researchers agree that diet has a strong impact on reducing the incidence of high cholesterol. Studies show that consuming high levels of saturated fats and some oils significantly increases the blood levels of LDL cholesterol. Therefore, the current medical recommendations lean toward following a diet low in meat and dairy products, reducing overall fat consumption. Additionally, exercising regularly helps maintain proper weight and reduce cholesterol levels with the added benefit of improving overall cardiovascular health. A diet low in saturated fats and a consistent and age-appropriate exercise program go hand in hand with acceptable cholesterol levels.  Patients with hypercholesterolemia who achieve their ideal weight as a result of diet and exercise typically see a reduction in cholesterol serum levels. Also, bi-yearly check ups are recommended to assess the blood cholesterol levels of patients, as well as to allow the physician to better manage the blood test results (Henkel 24). A typical visit with the doctor includes a follow-up chart of weight and overall heart screening including normal pulse, respiratory capacity and any symptoms indicative of cardiac problems. Blood test results are analyzed for total cholesterol levels as well as individual LDL and HDL levels. Hemoglobin and other blood lipids, such as triglycerides are screened as well. Hemoglobin transports oxygen in the blood, a vital component for a healthy cardiovascular system. Statin drugs are the prescription medicines of choice when diet and exercise are not enough to control hypercholesterolemia. They reduce blood cholesterol by blocking the synthesis HMG coenzyme A reductase, a liver enzyme necessary for producing cholesterol (Colpo 85). Furthermore, Colpo mentions that statins prevent the formation of plaque, and even reverse atherosclerosis, according to studies performed on laboratory rabbits (85). Additionally, and this is very important as it relates to the inflammatory nature of heart attacks, Colpo states that: In research with mice, statins markedly reduce measures of both inflammation and atherosclerosis, despite little change in serum cholesterol levels. In humans, statin therapy produces significant reductions in C-reactive protein, a marker of inflammatory activity that has repeatedly been associated with increased cardiovascular risk (86). Pharmaceutical drugs such as Lipitor and Crestor are widely prescribed nowadays, with additional cardiovascular fringe benefits that go beyond lowering cholesterol levels, as mentioned in the previous paragraph (Colpo 86). The synthesis and metabolism of cholesterol is a complex process that directly affects cardiovascular health. Regardless of family history, exercise, diet, and proper administration of prescription drugs successfully help reduce overall cholesterol levels, including lowering the levels of LDL. However, as with any medical condition, more research is necessary to better understand the complexity of cardiovascular disease and exactly how elevated blood cholesterol and in particular low density and high density lipoproteins affect its onset. Byrne, Kevin P. Understanding and Managing Cholesterol: A Guide for Wellness Professionals. Human Kinetics Books, 1991. Colpo, Anthony. â€Å"LDL Cholesterol: Bad Cholesterol, or Bad Science?†Journal of American Physicians and Surgeons Volume 10 Number 3 (Fall 2005): 85-86. Henkel, John. â€Å"Keeping Cholesterol under Control.†FDA Consumer            Magazine. (January February 1999): 22-24 framingham.com/heart http://info.britannica.com http://science.jrank.org/pages/1454/Cholesterol-History.html McKusick, Dr. Victor A. John Hopkins Directory of Genetics Support            Groups, Services and Information (2006): 298-299
Tuesday, March 3, 2020
The Truth About Famous Black Inventors
The Truth About Famous Black Inventors Quite a few of our readers have written asking me to clear up some facts about African American inventors in a sort of mythbuster manner. Much of the discussion has centered around who was the first person to invent a comb, elevator, cell phone, etc. African American Patents When an inventor files for a patent, the application form does not require a person to state his/her race. Thus little was known about early African American inventors. So librarians from one of the Patent and Trademark Depository Libraries decided to compile a database of patents granted to black inventors by researching patent applications and other records. These compilations include Henry Bakers Patents by Negroes [1834-1900]. Baker was a second assistant patent examiner at the USPTO who was dedicated to uncovering and publicizing the contributions of Black inventors. The database listed the inventors name followed by the patent number(s), which is the unique number assigned to an invention when a patent is issued, the date the patent was issued and the title of the invention. However, the database was misunderstood as readers falsely assumed that the title of the invention meant that the inventor had invented the first comb, elevator, cell phone and such. In the case of Henry Sampson, readers even misunderstood the title of gamma cell to mean Sampson had invented the first cell phone. Black Myth or Black Fact? This has led to writers publishing misleading articles that assume that every invention mentioned in the database would not have been invented if black people did not exist. Even worse are other writers who have written counterpoint articles that falsely give the impression that black inventors have not achieved great things. Understand that titles are required by USPTO law to be as short and specific as possible. Nobody entitles their patent applications The First Comb Invented or The 1,403th Comb Invented. You have to read the rest of the patent to find out what new improvements that the inventor is claiming. And nearly all patents are for improvements to pre-existing items. Did you know that Thomas Edison, who was not the first person to invent a lightbulb, invented over fifty different lightbulbs? Misleading the Public? Not one of the black inventors lied in their patent applications or stated that they had invented something totally new when it was merely an improvement. However, I have read articles that imply that these inventors have done something terrible. For example, take my article on John Lee Love. Nowhere do I state that John Lee Love invented the very first pencil sharpener, but the tone is favorable and shows the respect I have for Love as an inventor. Another website uses a headline that read Pencil Sharpener - John Lee Love in 1897? No! This harsh tone puts the inventors achievements in a negative light. However, these were still real inventors who received real patents at a time when it was rare and difficult for a person of color to do so. Why Recognizing Back Inventors Is Important My database list of African American patent holders holds historical value far beyond winning the first race. It has led to research that answered many important questions. Questions such as: Who were the first African Americans to receive a U.S. patents?What were African American inventors inventing during the 19th and early 20th centuries?Did early black inventors profit from their inventions?What are contemporary African American scientists and inventors achieving today? About Henry Baker I believe wholeheartedly that inventors make the best people. And while I will continue to maintain the historical aspects of the database and update the database with current inventors, what we know about early African American innovators comes mostly from the work of Henry Baker. He was an assistant patent examiner at the U.S. Patent Office (USPTO) who thankfully was dedicated to uncovering and publicizing the contributions of Black inventors. Around 1900, the Patent Office conducted a survey to gather information about black inventors and their inventions. Letters were sent to patent attorneys, company presidents, newspaper editors and prominent African-Americans. Baker recorded the replies and followed-up on leads. Bakers research also provided the information used to select black inventions exhibited at the Cotton Centennial in New Orleans, the Worlds Fair in Chicago and the Southern Exposition in Atlanta. By the time of his death, Baker had compiled four massive volumes.
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