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...he cause of malaria and how it infects humans is now known, like most diseases, it has been misunderstood. The Greek physician Hippocrates described malaria in his writings during the 400s BC. Documents from early civilizations in China, the Middle East, and Egypt also show evidence that malaria was known to these cultures. Throughout history—and even today—outbreaks of malaria have often been associated with warfare, migrations, and other societal disruptions. More soldiers have been lost to malaria than to bullets in the wars of the 20th century. Historians believe that malaria was brought to the Western Hemisphere by European explorers. The first recorded malaria outbreak in the Western Hemisphere occurred in 1493, and the disease was common during the era of European exploration and settlement in the Americas. The first malaria treatment emerged in 1638, when Spanish Jesuit missionaries brought cinchona bark—the source of quinine—back to Europe from South America. Tonic water, which contains quinine, was developed in an attempt to make the drug more palatable. Early investigators believed that malaria was caused by bad or contaminated air (the Italian word “mal’aria” means “bad air”). In the 1870s, with the recognition of a variety of disease-forming microbes, some scientists believed that it was caused by a bacterium. Koch's (1843-1910) postulates (1881), although not specifically related to malaria, were established to prove that a particular microorganism is the cause of a particular disease. This impacted immensely on future scientists and physicians in their own study of microorganisms. In 1884 French physician Charles Laveran (1845-1922) identified that a protozoan called Plasmodium caused malaria. He argued that malaria lived in the blood of the sick person, destroying red blood cells and giving off poisonous substances into the blood stream. Through several more species of Plasmodium were identified, the mode of their transmission was still unclear. Sir Patrick Manson (1844-1922), the world authority on tropical disease at the time, in 1877 demonstrated that the mosquito Culex fatigans transmitted a minute parasitic worm from person to person. He later suggested that mosquitos might also be the vectors responsible for the transmission of malaria. After years of tireless independent research and serving as a medical officer in India, British physician Ronald Ross (1857-1932) began experiments to answer this suggestion. Ross allowed mosquitoes to bite patients who had malaria. He would then dissect the stomachs of the mosquitos to see if he could find the same small black granules, or cysts, that could be found in infected human blood. On 20 August 1897,on what Ross called ‘Mosquito Day’ he found a cluster of small black granules in stomach tissue of an Anopheles mosquito. He had found oocytes in the stomach wall. Ross was able to establish the life cycle of the malarial parasite and the role that mosquitoes play in its transmission. He was awarded the Nobel Prize for Medicine in 1902 for his work on malaria. His discovery had found that vectors were responsible for infecting humans; researchers now knew that they had to control vector populations to limit the spread of disease. Wet areas - where mosquitoes bred - were drained and mosquito netting was introduced. Quinine was used to treat malaria sufferers. Therefore, malaria appeared to be under control. However when soldiers in World War I suffered ongoing bouts of malaria once they had left such tropical areas as Africa and Asia, researchers knew that the parasites were resisting treatment. Further measures were therefore taken to contain the disease. The discovery of the insecticide DDT - a very powerful organochloride insecticide - in 1942 and its first use in Italy in 1944 made the ideal of global eradication of malaria seem possible. Subsequently, widespread systematic control measures were introduced but it did not take long for more chemical and drug resistant forms of protozoa to appear. Environmental changes - such as the flooding of land for rice growing, the removal of cattle (alternative hosts to humans) and global warming - are contributing to the spread of malaria into areas where it is not normally found. For example, it has been predicted that malaria will spread to Australia, Canada, the United States and Europe. Efforts to develop a better understanding of the malaria parasite’s biology continue today with an international program to decipher all the genetic material of Plasmodium falciparum. Human Genome Project Procedures The Human Genome Projects main goal is to gain a basic understanding of the entire blueprint of a human being. The project involves: • Genetic mapping of the human genome - identifying the location of at least 3000 genetic markers on the DNA, spaced across all the human chromosomes. • Physical mapping of the human genome - cutting each chromosome into fragments and then determining the correct order of the pieces. • DNA sequencing - determining the exact order of the nucleotides on each chromosome. • Analysing the genomes of other organisms - Including the bacterium Escherichia coli, the yeast Saccharomyces cerevisine and the plant Arabidopsis thaliana. It was thought that looking at the genomes of other organism would not only provide a useful comparison but also increase the speed of development of new molecular techniques that could be used for the research. The ultimate goal of genomic mapping and sequencing is to associate specific human traits and inherited diseases with particular genes at precise locations on the chromosomes. The successful completion of the genome project will provide an unparalleled understanding of the fundamental organisation of human genes and chromosomes. It promises to revolutionize both therapeutic and preventive medicine by providing insights into the basic biochemical processes that underlie many human diseases. Mapping is the construction of a series of chromosome descriptions that depict the position and spacing of unique, identifiable biochemical landmarks, including some genes, which occur on the DNA of chromosomes. The process of physical mapping involves making large-scale maps of landmarks that lie along the landscape of the chromosomal DNA. The landmarks that have been used are short pieces of DNA that have already been sequenced. These sequences are then used as tags for their chromosomal environment. The order of these tags relative to all other tags on a chromosome is then deduced by another series of biochemical tricks. This involves cutting chromosomes into small pieces, finding out which of our landmarks belong to which chromosomal fragment and then trying to reassemble this whole into some semblance of its former self. During this process, the order of the landmarks can be deduced. Many copies of the cut fragment being studied may be made using PCR Technology. These fragments are labeled at one end with radioactive phosphorus as a reference point. Samples are then cut by one of two different restriction enzymes or by a mixture of both enzymes. The sizes of the DNA fragments produced are determined by gel electrophoresis and their position on the original fragment is deducted. Genes or known DNA sequences on chromosomes can be identified using genetic probes in hybridisation experiments. The genetic markers on chromosomes identified by DNA sequencing have assisted the genetic mapping of chromosomes. In June 2000, scientists announced the completion of the draft Human Genome Map. Special issues of Science (Feb. 16, 2001) and Nature (Feb. 15, 2001) contain the working draft of the human genome sequence. A final version is expected to be completed no later then 2003. The sequencing has thus far been completed for only two chromosomes - 21 and 22. Benefits Rapid progress in genome science and a glimpse into its potential applications have spurred observers to predict that biology will be the foremost science of the 21st century. Technology and resources generated by the Human Genome Project and other genomics research are already having a major impact on research across the life sciences. The benefits of this project fall into two categories, each associated with improvements in knowledge, technology and computing. Short-term benefits involve the better diagnosis of genetic disease. Screening of the respective populations has led to a significant decrease in the number of people suffering from such diseases. Once there is a final map of human genes, there will be less emphasis on treating diseases and more emphasis on establishing risk and preventing disease. The genome map will be used to study more then 4000 hereditary diseases and the reasons for uncontrolled cell division, such as in cancer. Long-term benefits involve the better understanding of how our body is controlled by genes. Great progress has been made in understanding genetic diseases caused by a single gene; however many diseases result from the effects of several genes. As was shown with gene cascades, not only does one gene act after another, but it also can have different effects, depending on when and where in the body it is active. One way such a study is carried out is to isolate mRNA (messenger RNA) from active cells and to use reverse transcriptase to generate cDNA. This cDNA can then be used to both locate the gene and compare it with other genes to search for similarities. Researchers can then determine when genes are active, where they are located (such as in which tissues) and to what affect a person's state of health has on their activity. Overall, the information obtained from this project will increase our understanding of biological processes in both other organisms, and ourselves and will form a basis of biological research for many years to come. Limitations There are a certain number of limitations that are also placed on the Human Genome Project. Geneticists will not be able to look at a person's DNA sequence and predict everything about the appearance and characteristics of that person. Even if geneticists can identify segments of DNA as genes, the vast majority of the genes they discover still will have unknown functions. In addition, many human traits such as body stature and intelligence result from multiple genes, and the exact number of genes that might contribute to such a trait is not obvious, nor are the ways in which those genes interact. An individual's genetic make-up greatly contributes to the type of person he or she is, but environmental variables such as diet, education, climate, family values, and access to health care also play a considerable role in determining an individual's characteristics. Even in single-gene disorders, there usually is considerable variation in the expression of the gene. This variability may result from different mutations in the same gene, environmental effects, interactions with other genetic features, or any combination of these factors. Thus, even when geneticists discover a disease-related gene in an individual, they cannot always predict the exact course of the disorder. Although it may appear that our genes are relatively stable, the human genome changes continually because of errors in DNA replication. Genes responsible for genetic disorders may be inherited from one or both parents, or they may arise from new mutations because of errors in the replication of an individual's DNA. It is unlikely, therefore, that a geneticist could absolutely exclude the possibility of a genetic disorder by examining an individual's genome. New mutations are more likely in X-linked and autosomal dominant than in recessive disorders. There has been criticism of the huge amount of money spent on the project. The value of the results compared to other ways of spending the same amount of money to help and improve the human condition has been questioned. Human genetics is a sensitive issue. There are concerns that genetic information resulting from the project may be misused and lead to discrimination between people of different genotypes. For example, those with a genetic predisposition to certain diseases. Although the project is developing guidelines addressing legal, ethical and social issues, the public, for the most part, has not yet thought about or debated these topics in sufficient depth. Skin Cancer: - Public Education Skin Cancer is one of the main priorities targeted in the cancer control area of the National Health Priority Areas initiative. (Cancer Council Australia: http://www.cancer.org.au) Public education systems usually place more emphasis in controlling and preventing the disease rather then curing it. The Cancer Council New South Wales provides public education services on their web site (http://www.nswcc.org.au). There are many different skin cancer prevention initiatives and programs. Whilst they all aim to reduce the rates of skin cancer, each has its own set of specific objectives and importance. The first mass media skin cancer prevention campaign began in 1981. This was known as the 'Slip, Slop, Slap, Wrap' program, which became well known and understood by Australians and is still used today to promote prevention. Its role is important in reminding citizens of the following sun protection methods: • SLIP on a shirt • SLOP on sunscreen • SLAP on a hat • WRAP on clothing to cover exposed skin. This was further enhanced by the adolescent-focused mass media campaign known as 'Me No Fry', which was conducted in 1991 through to 1995. In 1996, The Cancer Council NSW began the SunSmart program to meet the need for improved sun protection practices in outdoor sport and recreation. The program continues today. As a sport-loving nation, most Australian children and the majority of adults are involved in outdoor sport and recreation as participants, organisers, officials or spectators. While this involvement has many health benefits, exposure to UVR during these activities increases the risk of skin cancer. Therefore strategies to reduce exposure of children and adults involved in outdoor sport and recreation is an important part of any skin cancer prevention program in Australia. Its role is to provide information on sun protection to be included in training for volunteer and professional sport administrators and to distribute resources to support sun protection policy and practice in sporting organisations. The hope is to achieve continual improvements in sun protection practices and reduce the risk of skin cancer for everyone involved. During the summers of 1997, 1998 and 1999, The Cancer Council NSW and NSW Health Department jointly ran the Seymour Snowman Sun Protection Campaign. Children's sun protection was the main focus of the campaign. Epidemiological evidence indicates that sun exposure in childhood is a major contributing factor in causing skin cancer later in life. In addition, the results from a survey showed that parent behaviour in relation to their child's sun protection had much room for improvement. The key message was that unprotected exposure to the sun during the first 15 years of a child's life more than doubles their chance of getting skin cancer later on. Other messages included: • Effective sun protection involves a range of measure including wearing clothing to protect the skin, wearing a broad brimmed hat or legionnaires cap and using sunscreen. • Sun protection is for everyday, not just for special trips. • Sun protection is still important on cloudy days. As a result, the key message for the second year of the campaign was that effective sun protection involves a range of measures, not just sunscreen use. This new message was...