Experiment for Cancer Risk Factors

Experiment for Cancer Risk Factors Curiouser and Curiouser The case-control method used to identify risk factors for cancers relies on prior knowledge about the possible link between the cancer and the risk factors. It is a powerful method as the following two cases show. Asbestos In the 1970s, a series of studies identified the risk factor for a rare form of lung cancer called mesothelioma. Case-control studies pinpointed the risk to certain professions: insulation installers, shipyard workers, etc. The statistical analysis pinpointed the risk factor to be exposure to asbestos. Subsequent tort litigation and government oversight precipitated a reduction in occupational exposures to asbestos, reducing the risk of mesothelioma. Diethylstilbestrol (DES) Diethylstilbestrol (DES) is a synthetic hormone prescribed to pregnant women in the 1950s to prevent premature deliveries. In 1971, case-control studies found that women with vaginal and uterine cancer had not been exposed to estrogen directly, but their mothers had been. DES, the carcinogen, did not cause cancers to women treated with the drug, but it caused cancers to their daughter who were exposed to the drug in the womb. *** But what if the exposure responsible for the disease is unknown? A Test for Chemical Carcinogens Normally, a strain of Salmonella, a bacterial genus, cannot grow on galactose. But when exposed to certain chemicals, it could acquire a gene mutation that enables it to grow on galactose. By counting the number of growth-enabled colonies form, one can quantify the mutation rate in any experiment. In the late 1960s, Bruce Ames, a bacteriologist at Berkeley, used this technique to test thousands of chemicals on their capacity to create mutations in Salmonella, and created a catalog of mutagens chemicals that increased the mutation rate. He observed that chemicals that scored as mutagens tended to be carcinogens. Ames didnt know why mutagens could induce cancer. But he had demonstrated a practical way to find carcinogens. Hepatitis B virus (HBV) In the early 1970s, Baruch Blumberg, a biologist in Philadelphia, discovered that a human hepatitis virus can cause chronic inflammation that leads to cancer. In 1966, Blumberg discovered that individuals carrying the Au antigen (a blood antigen present in several Australian aboriginals) often suffered from chronic hepatitis. Upon further analysis, he found out that au was not a blood antigen but a viral protein floating in the blood. Blumbergs lab isolated the virus in the early 1970s, and called the virus hepatitis B virus (HBV). HBV infection caused a broad spectrum of diseases, ranging from acute hepatitis, to chronic cirrhosis in the liver, and to hepatocellular cancer. HBV is a live carcinogen capable of being transmitted from one host to another. By 1979, Blumberg and his team had found a vaccine for HBV. The vaccine cannot cure the cancer, but it can reduce the incidence of HBV infection. Helicobacter Pylori (H. Pylori) In 1979, at the Royal Perth Hospital in Australia, Barry Marshall and Robin Warren wanted to investigate the cause of gastritis. Patients with gastritis are   predispose to peptic ulcers and stomach cancer. Warren believed that gastritis was caused by a yet unknown species of bacteria. But he was ridiculed by mainstream doctors who did not believe any bacteria could live in the stomach. To prove his point, Marshall and Warren set out to culture the bacteria using brushings from patients with ulcers. But no bacteria grew out. Over a busy Easter weekend in 1982, Marshall had forgotten to examine the culture dish for bacteria for a few days. When he remembered and went to examine them, he found bacteria colonies growing out in the dish. Warren and Marshall called it Helicobacter pylori (H. pylori). To prove H. Pylori caused gastritis, they inoculated pigs with the bacteria. But the pigs did not get ulcers. In 1984, after failed attempts to infect piglets, Marshall fasted until 10 am and then drank a Petri dish containing cultured H. Pylori, expecting to develop an ulcer. Within a few days, Marshall was violently ill, and diagnosed with gastritis. H. pylori was indisputably the cause of gastritis. By the late 1980s, several epidemiological studies had linked H. pylori-induced gastritis with stomach cancer. Randomized trials run on the western coast of Japan showed that antibiotic treatment reduced gastritis and gastric ulcers, and reduced the incidence of gastric cancer. But the it would not cure the cancer once manifested. A Spiders Web If cancer truly transitioned from a precursor lesion precancer to its full-blown form slowly, and methodically, then perhaps one could intervene by attacking its precancer, thwarting the progression of the cancer at its earlier stages. There are two forms of prevention. In primary prevention, you prevent a disease by attacking its cause. For example, stop smoking for lung cancer, or a vaccine against HBV for liver cancer. In secondary prevention, you prevent a disease by screening for its early presymptomatic stage. Pap smear and mammography (discussed below) are examples of secondary preventions. The Pap Smear Secondary Prevention for Cervical Cancer George Papanicolaou, a Greek physician, arrived in New York in 1913. After a few months selling carpets, he found a research position at Cornell University studying the menstrual cycle of guinea pigs. He found that cells shed by the guinea pig cervix could foretell the stages of the menstrual cycle. By the late 1920s, Papanicolaou had extended his technique to human patients.   In 1928, he reported that uterine cancer could be diagnosed by means of a vaginal smear. But the importance of his work was not recognized. Between 1928 and 1950, Papanicolaou delved into his smears ferociously. He became known for his invention of the Papanicolaou test, commonly known as the Pap smear or Pap test. He knew normal cervix cells change in step-wise fashion in time. Might cancer cells also change in a slow stepwise way from normal to malignant? Could he identify intermediate stages of cancer? A thought occurred to him at a Christmas party in 1950. The real use of the vaginal smear was not to find cancer, but to detect its precursor. In 1952, Papanicolaou convinced the NCI to launch a clinical trial of secondary prevention using his smearing technique. In the cohort of about 150,000, 555 women had invasive cervical cancer, while 557 had preinvasive lesions. Early stage preinvasive lesions were curable by a simple surgery. The women with preinvasive lesions had no symptoms. Had they not been tested, they would never have suspected they would develop cervical cancer. The average age of diagnosis of women with preinvasive lesions was about 20 years younger than women with invasive lesions. The Pap smear would detect cervical cancers at an early stage while it is still curable 20 years before they become invasive, giving women a chance to treat it before it evolves into cancer. Mammograms Secondary Prevention for Breast Cancer In 1913, Albert Salomon, a German surgeon, performed a study on 3,000 mastectomies. He studied the X-rays of the amputated breasts after mastectomies to detect the shadowy outline of cancer. Salomon called his technique mammography. He was able to establish the difference as seen on an X-ray image between cancerous and non-cancerous tumors in the breast. But his studies were interrupted by the Nazis in the mid-1930s. He lived in a concentration camp until 1939 when escaped the camps to Amsterdam and vanished underground. Mammography, as he called his technique, languished in neglect. By mid-1960s, with radical surgery being challenged, mammography re-enter X-ray clinics, championed by radiographers such as Robert Egan. Egans mammograms could now detect tumors as small as a grain of barley. But would screening women to detect such early tumors save lives? HIP Trial In 1963, three men set out to investigate whether screening asymptomatic women using mammography would improve mortality from breast cancer. The three men were Louis Venet, a surgeon; Sam Shapiro, a statistician; and Philip Strax, an internist. They wanted a randomized, prospective trial using mortality as an end point to test mammography. The trial, launched in December 1963, was kept simple. Women enrollees in the New York Health Insurance Plan (HIP) between 40 and 64 years old were divided into two groups. One group was screened with mammography, and the other not. If a tumor was detected by mammography, the women would be treated according to the conventional treatment available at that time. In 1971, the initial findings of the trial were remarkable. 62,000 women participated; about half had been screened by mammography. There had been 31 deaths in the mammography group and 52 deaths in the control group. The percentage reduction in mortality from screening was about 40 percent. Breast Cancer Detection and Demonstration Project The positive results of the HIP trial prompted the American Cancer Society to launch a called the Breast Cancer Detection and Demonstration Project (BCDDP). The project, backed by Mary Lasker and virtually every cancer organization in America, intended to screen 250,000 women in a single year. Problems with the HIP study As the BCDDP forged ahead, people were casting doubts over the HIP study. The study had a potential flaw. They had decided to exclude women with prior breast cancer. So they dropped women who had had cancer from each group. But they may have over-corrected: more patients with prior cancer were dropped from the screened group. Critics now charged that the excess mortality in the control group was due to the fact that it was mistakenly overloaded with patients with prior breast cancer. The Canadian Trial In Canada, researchers launched their own mammography trial in 1980. But there was a flaw with the study: a woman was randomized after her medical history and examination. The allocations that emerged after the nurse interviews were no longer random. Women with abnormal breast were disproportionately assigned to the screened group. That explains why the results of the CNBSS were markedly negative: The breast cancer mortality of women in the screened group was higher than the unscreened group. Malmà ¶ Mammographic Study In 1976, 42,000 women enrolled in the Malmà ¶ Mammographic Study. Half of the cohort was screened yearly, and the two groups have been followed closely ever since. In 1988, the study reported its results. Women older than 55 had benefited from screening, with a reduction in breast cancer mortality by 20 percent. Younger women had no benefit from screening. In 2002, an analysis combining the experience over fifteen years was published in the Lancet. In aggregate, for women aged 55 to 70, mammography screening had resulted in 20 to 30 percent reductions in breast cancer mortality. But for women under 55, the benefit was negligible.

Chinook Salmon :: essays research papers

Chinook Salmon Environmental Science Wednesday, February 26, 1997 Among the many kinds of fish harvested each year by commercial fisheries is the Oncorhynchus tshawytscha or Chinook salmon. The United States catches an averages of about three hundred million pounds of salmon each year. However some Chinook salmon have been recently listed as threatened. Man has been the main cause for the decline in Chinook salmon populations. The populations of Chinook salmon have declined for several reasons. Hydropower and it's destructiveness to the environment, pollution, and overfishing are the three main causes for the decline. The Chinook salmon is known for traveling the greatest distance back to its spawning grounds, often traveling one to two thousand miles inland. This long journey is now often interrupted by hydroelectric plants. Hydropower is a very good alternative resource for power, however it is very damaging to our salmon populations. The dams block off rivers, which block the salmon's path back to their breeding grounds. The salmon go back to the same areas, just as their ancestors did, to lay their eggs. The hydropower plant's turbines are also very dangerous to young salmon. Many of them are killed by the giant turbines on their way back to the ocean. Killing off many of the salmons new generation. Pollution is also a killer of many Chinook salmon. Pollution caused by sewage, farming, grazing, logging and mining find it's way into our waters. These harmful substances kill many species of fish and other marine life. The Chinook salmon is no exception. The chemicals are dumped into the rivers and streams and eventually these chemicals find their way to the ocean, polluting and effecting each area they pass through. The largest contributor to the decline in the Chinook salmon population is the commercial fishing industry. From a period of 1990-1992 815,000 Chinook salmon were caught by commercial fisheries. This does not include the 354,000 recreational catches. Commercial fishing is a big industry. Commercial fishers use nets, which they pull by boats. Some nets are designed so the holes in the nets are large enough for the head of the fish to fit through, and then the mesh gets caught in the fish's gills. Others are designed to circle around a school of fish and then is drawn shut. New technologies have developed factory stern trawlers which easily haul netloads of up to 100 metric tons of fish. However, when catching the salmon, fisherman use pound nets to catch the fish on their way to their spawning grounds. The average annual salmon catch in just the United States is about 300 million pounds, of that about 60 percent is canned.

Too Many NGO’s, Not Enough Leaders

Non-profit Organizations in our time, has become the blood of every civil society; providing progressive benefits as well as the necessary aids for marginal groups/sectors of society. It would however be infer by the word â€Å"non-profit† that it literally mean, gaining no profit from a particular NGO. Thus, it would be a common problem for these organizations, the funds for their activities, employees’ salary, and trainings. Overview Non-profit organizations based on the research done by the Bridgespan Group (2006), faced the problem of having none if not too little resources to develop a large pool of highly competitive mangers within their organizations. Same study also indicates that over the next decade, an additional of more than double of today’s managers, will be needed by these organizations. One of the key reasons for this deficit would be the continuously increasing number of NGO’s, the retirement of leaders or the disbanding of a leader to seek greener pasture outside their non-profit organization (Bridgespan, 2006). With this in mind, there is a need to resolve this problem for leadership deficit. This paper aims to give suggestive ideas and proposals on how to address the growing need for leaders in NGO’s. Proposed Answer to the Leadership Deficit Publicity should come first. There’s a lot of ways to advertise your company. With this, you are definitely hitting two birds in one stone. First, through advertising, your endeavor and cause would be known to the public and it would be very beneficial since, major sponsors from your country or abroad would be pouring their support on your company. It would also be a good start to partner with media networks (because media has the fastest access to money). Second, is that, you would be able to attract more and more people and volunteers to work for your organization. The more volunteers you have, the lesser the budget for mobilizing labor pool. Bridgespan (2006), agree that though it may sound paradoxical, the presence of â€Å"funders† strengthen the NGO and its leadership demands through its demands that require to be met. Enhance Compensation for NGO Leaders and Executives Although some would find it their ends to reach their full potential in engaging themselves in â€Å"philanthropic† activities, it would not be denied that even these people has the economic needs, necessary for them and their families to survive. Leaders of the NGO would be much motivated if they think that their efforts and mental investments in the company are well compensated (Bridgestar, 2006). Invest within the people of your organization There is always an objective measure to quantify efficiency. Begin, by pointing out who among the junior employees in your NGO, have the capacity for hard work, mental alertness, loyalty and the necessary qualities such as greater sense of responsibility. Invest in them. Those in their senior years and are about to retire, should worked hands-on with their volunteers and juniors. Try to impart to them the knowledge that you have long held to remain the executive of your organization. Investing in these young people is cheaper and gradual than recruiting from the outside. Whenever, potential leaders are already identified, start by imparting them a higher level executive strategies through training and development. The training strategy should be feasible, cheaper and would instill the value of â€Å"continuity† among the set of leaders. Also, discuss the trend in the leadership deficit to these new potential leaders and asked their opinions and suggestions about it. Provide Intergenerational Discussion By this, it means a link between the senior (baby boomers) and the future junior leaders. A discussion on the aspirations, the rewarding milieu, hindrances to loyalty within an NGO and difficulties among these future leaders, would give an insightful bird’s-eye view on what generation gap means and how to address this hindrance. A good background on the subjects mentioned above would be the basis for creating a better framework for recruitment, training and providing increased compensation and other benefits. Senior leaders should always recognize the difference in technology they have handled before compared to these new junior potential leaders and the importance of giving the latter the right improvement for their creativity, growth and development, and fulfillment as prospective leaders of the company (NCNA, 2007). A greater Plan for the New Batches of Leaders More often than not, being a leader in an NGO neither confines anyone to the four walls of the organization, nor requires anyone to devote his/her life working for the organization. With this, it should not be overlooked, that at a more personal level, leaders tend to have their social activities outside the organization. Forming a girls club, for instance is another role a leader may play. In this manner, NGO’s should male use of this event as an advantage not otherwise. For instance, a party or a training involving their organization may farther contribute to higher employees’ satisfaction and may open venue for new prospective leaders, if not loyal employees of the organization (The Cancer Council, 2007). Given all the proposed alternatives above, NGO should reconsider the strategies that they have employed in their organizations. Above all things, for these company to realize the latter propositions, there is a must to strengthen their instability through increasing their sponsors and funds; with this all other would be a lot easier and faster. References Girls Night In. (2007). The Cancer Council NSW. Retrieved, January 22, 2008 Leadership Matters. (2006). Bridgestar.org. Retrieved, January 23, 2008, from https://www.bridgestar.org/Resources/Newsletters/2006/March2006.aspx Tierney Thomas. (2006). The Non-Profit Sector’s Budget Deficit. The Bridgespan Group. Retrieved, January 22, 2008, from http://www.bridgespangroup.org/PDF/LeadershipDeficitWhitePaper.pdf                           

Exploring the Theme of Pride and Prejudice Essay - 2643 Words

How does Jane Austen explore the theme of Pride and Prejudice in the novel? The original title of Jane Austens novel, Pride and Prejudice was First impressions. From this title it is clear that Jane Austen wanted to convey to the reader the importance of first impressions and how we form them so quickly. Other themes of the novel include pride, prejudice, conceit and vanity. Most people have these feelings or opinions without even realising it. Pride is a feeling of satisfaction that you have done well, however, it can also mean that you feel better than others. Pride can be linked to vanity, which can be described as a feeling of excessive pride regarding aspects of yourself, for example, your looks or abilities.†¦show more content†¦Elizabeths prejudice against Darcy is fuelled when she hears from Wickham that Darcy has treated him wrongly. Elizabeth accepts Wickhams story without exploring it fully because she believes that he is a gentleman and so is trustworthy. This is another example of how first impressions can be wrong, as Wickham is not a gentleman as Elizabeth first thought and has not told Elizabeth the whole truth about why Darcy treated him wrongly. When Elizabeth finds out the vital information that Wickham has not mentioned her opinion of both Wickham and Darcy changes dramatically. This is a crucial point in the novel as this is when Elizabeth realises how easily she has formed prejudices and opinions about people that are wrong. Austen has also guided the reader to have the same opinions, as Elizabeth and this is the point in the reader realises that they too have formed inaccurate opinions and prejudices against characters. At the beginning of the novel the reader is intended to dislike Darcy. Austen creates this through the use of language by the omniscient narrator. 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Though their romance is more reserved, the love that Elizabeth and Darcy share is no weaker than that of Jane and Mr.Roc hester. The way that Bronte and Austen approach the theme of love, and the styles of characterization they useRead MoreMarriage Vs. Love Jane Austen s Pride And Prejudice 1461 Words   |  6 PagesJake Hammel Ms. Salrin Love and Romance 17 November 2015 Marriage vs. Love Jane Austen, author of Pride and Prejudice, wrote in an era where considerations of social class and economic status were central to the institution of marriage. This notion is demonstrated throughout the novel by exploring character’s ideas and definitions regarding love and marriage. The main character, Elizabeth, defies almost all stereotypes of early 19th century women in England. She, unlike Charlotte and Jane, believesRead MoreThe Hobbit1067 Words   |  5 Pageschildren’s tale to an epic, the main character Bilbo undergoes a series of development, his experiences often overlapping with ordinary people. Reading the Hobbit will provide teens with opportunities of exploring the importance of several common but serious topics. People may encounter many of the themes presented in the book elsewhere repeatedly, but it’s possible that they never appreciated the applications it might have on themselves. When teens read the Hobbit, they perceive it as a simple fic tion